(CNN) There are few tickets in sport more coveted than Wimbledon's Centre Court debenture offerings. But they don't come cheap.

On Thursday, 2,520 five-year passes went on sale, with each debenture costing £80,000 ($105,000).

The annual fortnight of grass-court tennis is one British sport's crown jewels and Wimbledon's debenture seating is like sporting gold dust, providing its owner unrivaled access at the sport's oldest grand slam tournament.

As well as granting admission to every Centre Court game between 2021 and 2025, the debenture also potentially offers a tidy investment opportunity. One such case in February saw a pass-holder buy a five-year debenture for $66,149, before selling the final two years of the premium ticket for $138,892 three years later.

Some ticketholders sell their passes for certain days of the annual championship, while others have been known to resell the pass in its entirety for a bumper price.

"If you like tennis, a visit to Wimbledon is like mecca," said Claire-Estelle Bertrand, marketing and communications manager at Wimbledon Debenture Holders , one of a number of official debenture ticket resale agents. "It's prestigious, it's rarefied class but most importantly its quintessentially British.

"They really are the most sought-after tickets in the world. Not only do they give you the best seats to see the world's best tennis, but they really do grant you access into an exclusive world where you can meet other global influencers and meet current and past tennis champions.

Roger Federer won his eighth Wimbledon crown in 2017, beating Marin Cilic in straight sets.

"I personally feel these seats are the absolute best in the house, you have the opportunity to sit alongside the player family boxes and the royal box."

The package, which entitles holders to one reserved seat on Centre Court per day of the Championships over the course of the five years, includes access to special viewing rooms, which allow debenture-holders to watch action on the outside courts from an exclusive space.

The facility also features an exclusive restaurant, which hosts dishes by famed chefs Albert Roux and Bryn Williams, as well as lounges, bars and a private car park -- though the debenture doesn't entitle you to free food and drink.

The sale, for which applications are open until May 10, could see the All England Club (AELTC) potentially raise close to $250 million.

"Whatever the seats end up going for, they are essential for the running of the club," said Bertrand.

"The money raised from debenture sales has paid for a number of improvements to the facilities, including the Centre Court roof and No. 1 Court.

2,520 of the 15,000 seats that make up WImbledon's Centre Court are allocated to debenture-holders.

"The All England Lawn Tennis Ground plc. uses funds from debenture sales to offset the considerable expense of running the AELTC and The Wimbledon Championships, none of which would be possible without funds generated by debenture holders."

The 2,520 debenture passes amount to 16.8% of Centre Court's seating and of the stadium's 15,000 available seats, just over half of the arena's capacity is made available to the public.

In an open letter from AELTC chairman Philip Brook to pass-holders in the 2018 debentures guide , he thanked buyers for their support. "Since 1920, debenture holders have played a leading role in helping us improve the Grounds," he said.

The importance of this latest five-year cycle is no different, with the AELTC preparing major redevelopment work of the Wimbledon grounds.

The club is in the midst of a renovating of No. 1 Court -- the second biggest show court after Centre Court, with the overhaul including the addition of a retractable roof, more seating and a two-level public plaza.

In December, a deal with Wimbledon Park Golf Club was agreed, which will see the AELTC purchase the neighboring club's 73-acre site in a deal worth $85.6 million, after a majority of the golf club's members voted to ratify the agreement.

The land, which is based across the road from the competition's main location in southwest London, has been mentioned by AELTC chiefs as a possible venue for Wimbledon's qualifying event.

The 2016 to 2020 debenture sales cycle raised $138.6 million after tax for the All England Club.

Wimbledon is currently the only tennis grand slam where qualifying tournament is not held on-site. The precursor to the tournament takes place nearby at Roehampton.

As well as freeing up space for the qualifying event, the adjacent estate will also give Wimbledon the opportunity to expand and improve its corporate facilities, with the other three grand slams having all recently upgraded their offerings.

The previous cycle of 2016 to 2020 priced debentures at $66,000 each, raising $138.6 million in the process. However, the debentures' reinvestment value highlight why demand for the five-year passes remain so strong.

As Tim Webb, a stockbroker at Dowgate Capital Stockbrokers -- the official partner for the secondary market in Wimbledon debentures, explained to CNN: "The last one which we did in February was at £105,000 ($138,000). And that is with two years left to run, so they have two years' worth of tickets. It was issued at £50,000 ($65,700) with five years, and it was traded at £105,000 with two years left in February.

"Supply and demand takes the price to wherever it is. I'm sure the majority of the people buying debentures are tennis-lovers. It is a wonderful experience and, obviously, people are prepared to pay a premium to get debenture tickets."

As well as profiting by trading on their passes, debenture holders are also able to sell on tickets for individual days.

For the upcoming 2019 Championships, resale prices range from $700 to $5,732 on the Wimbledon Debenture Holders website. The latter figure -- for a debenture resale ticket to the men's final -- represents nearly a tenth of the initial value of the entire 2016-20 cycle, emphasizing the reinvestment potential of purchasing a debenture.

The tournament organizers, however, are unconcerned by any propensity to resell and reinvest debentures. The transferability of the premium tickets is viewed as a privilege earned through the support given to the AELTC by the pass-holders. The resale or transfer of non-debenture tickets immediately invalidates them.

Among the benefits available to those who pay the premium, pass-holders are able to transfer and resell debentures for their own profit.

An AELTC spokesperson told CNN: "Debenture tickets are the only Wimbledon tickets which are freely transferable as the AELTC believes this is fair to those who have invested considerable sums in buying debentures."

Indeed, first refusal on renewal of the five-year ticket is given to previous holders as a mark of their financial commitment.

Though damage to early records has slightly clouded the official statistics, it is believed that some families' debenture passes date back to the concept's beginning.

"We believe that there is at least one family that has held debentures since inception," said an AELTC spokesperson.

In January, Brook also hinted that tournament organizers could look at changing its application process for regular tickets.

While debenture applications can be made online, regular bids for tickets from the United Kingdom are still made by mail -- a long-held tradition of the competition. Overseas, the ballot is now performed as an online process.

However, Brook, who is set to leave his role at the end of 2019, told the 2 Barrys Tennis Takeaway podcast : "It is hard work. You have to send in a form with a stamped-addressed envelope. We have for the last three or four years put our overseas ballot online. This is a bit of a test to see what happens.

Andy Murray won the Wimbledon title twice, becoming Great Britain's first champion at the All England Club in 77 years in 2013, before securing a second crown against Milos Raonic in 2016.

"We are looking closely at the whole question of the ballot and whether we might move it online. We are a bit worried about that, (as) we might be completely swamped with demand. Secondly, we think with a paper-based system it is harder for people to cheat."

The ballot has existed since 1924 -- making it four years younger than the debenture system, which first came into play in 1920. The funding from that initial cycle -- 99 years ago -- helped to fund the initial construction of Centre Court.

The nature of the public ballot, though, is such that entry simply offers applicants an initial place in the ticket draw, with demand far greater than the grounds' capacity.

The draw is then carried out electronically, allocating successful applicants with days and courts at random. Fans are unable to request specific days or courts, and have no choice over the allocated days, courts and matches.