Delirium will overcome the owners of either Watford or Crystal Palace at Wembley on Monday although, even as emotion erupts all around, the victorious could be forgiven for skulking to the back of the royal box to pinch themselves over what is to come. The spreadsheet projections scream mind-boggling numbers, figures to transform. It has become cliched to refer to the Championship play-off final as the richest game in world football, but the reality is both these sides are one calm finish amid the excruciating tension from an influx of at least £140m.

Those are the stakes at the national stadium, a staggering reward inflated by the new £5.5bn television deal that will ensure the team that finishes bottom next season walks away with around £63m. Manchester United claimed "only" £61.4m in winning the title this time around, a sum comprised of £15m in prize money, £33m from the Premier League share and £13.4m in live television engagements. Even relegation guarantees £59m in future parachute payments, to be spread over the next four seasons in tranches of £23m, £18m and two of £9m. Forfeiting the Football League "solidarity money", worth around £2.2m in the Championship, rather pales into insignificance.

Those headline figures draw the focus, the sums to which the Palace manager, Ian Holloway, was referring when failing to contain his enthusiasm ahead of his third play-off final in four years. "Just look at the size of the prize," he said. "The last time I fought for this [with Blackpool against West Ham last year] it was worth £90m. Now it's north of £120m. That's why people are buying Championship clubs and throwing money at it. Look at Cardiff. They've had seven goes, so well done to them this year. But, my God, if they hadn't made it how much would they have owed?"

Yet there are other lavish perks that pursue promotion. The clubs who collide at Wembley are roughly similar in terms of status, stadium potential and turnover, which the most recent accounts put at around £11m for Watford and £15m for Palace. Yet Gianfranco Zola believes success on Monday would lead the Pozzo family to prioritise their English acquisition over their other footballing interests, Udinese and Granada. Should the south London club go up, their four owners would anticipate corporate revenues rising to around £6m per year, and merchandise, advertising and sponsorship beyond £2m. Rolling hoardings cost second-tier clubs around £700,000 to buy, with the onus on the club to sell to prospective advertisers. In the Premier League those same boards are donated free of charge, with the manufacturers paying a further £1m fee to sell advertising themselves. It is a different world.

Then there are increased attendances. Selhurst Park regularly heaved close to its 26,000 capacity the last time Palace graced the top flight, in 2004-05, and increased ticket sales would swell the coffers by an estimated £12m. They already have more than 10,000 season ticket holders for next term courtesy of a late rush of sales in the week since they reached the final. The club's current turnover leaves them ranked around 300th across Europe; promotion could lift revenues closer to £100m, potentially hoisting them to around the 30th highest turnover on the continent.

"There is almost too much at stake," said the co-chairman, Steve Parish. "It's almost like walking into a casino and putting the future of the club on red or black. It's a 50-50 bet with which you might be able to transform your football club. Watford are not in a dissimilar position with us and I'm sure we'll both be looking at the riches and thinking we could probably make that go quite a long way and make a big change to the club."

There is, of course, a financial commitment that comes with promotion before the victors can start strengthening their squad. Players and management staff will be due bonuses for promotion, while former clubs will call in similar fees detailed in the small print of the deals that took players to either south London or Hertfordshire. The former Palace chairman, Simon Jordan, paid bonuses totalling £3m to players and staff in 2004 when Iain Dowie's side gatecrashed the elite, with the manager due a £500,000 one-off payment and receiving a 500% pay rise on a new contract. While lower this time, they would still amount to more than £3m in contractual obligations, with salary increases to follow.

The annual wage bill at Palace currently stands at around £12.5m, a figure that would rise dramatically even before attention turns to bolstering the squad. The money required to make Holloway's side competitive would be significant. "What would a win mean?" asked the Palace manager. "Total joy on Tuesday. Total panic on Wednesday."

The installation of television cabling and formal interview rooms at the stadium, so Sky, BT or foreign broadcasters can transmit smoothly from the arena, will cost around £1m, while the size of the pitch must conform with Uefa regulations. Watford already boast the required dimensions – with a pristine Desso surface – but Palace would have to extend the turf from 100m x 67m to 105m x 68m.

Yet these are niggles, acceptable costs in the context of the increased income that would allow both clubs to speed up plans to redevelop their respective stadiums. Watford's ramshackle East Stand is still condemned, with the owners claiming they will rebuild it in the Premier League. The derelict area between the Rous and Rookery stands will be renovated regardless at a cost of £1m.

Palace hope to tear down Selhurst's Main Stand. "In the current stadium, even if you are just in there over one season, you are looking at probably a £70-80m boost in revenue," added Parish. "If we can't spend half of that to have a good go, and the other half on the infrastructure of the club so that if we did come down we've got an even better chance of staying up the next time, there'd have to be something wrong." The opportunity is tantalising. To the victor, the spoils.

Crystal Palace (4-2-3-1; probable): Speroni; Ward, Delaney, Gabbidon, Moxey; Dikgacoi, Jedinak; Zaha, Garvan, Williams; Wilbraham.

Watford (3-5-2; probable): Almunia; Doyley, Ekstrand, Cassetti; Anya, Abdi, Hogg, Chalobah, Briggs; Deeney, Vydra.