Development teams vying to build a new convention center complex in downtown Jacksonville rolled out their plans Tuesday and attached some big price tags for what the city's financial obligation would be to make those concepts a reality.

One proposal would require the city to pay $1.2 billion over 25 years, while another put the amount at $936 million over 30 years. Officials still need to crunch the numbers on what the obligations would be for the third development team's plan.

A three-member evaluation committee listened to the developers for three hours Tuesday afternoon and will submit their scores next week to the Downtown Investment Authority board. The DIA board will decide Sept. 19 which development team gets the top ranking for building a new convention center, hotel and parking garage on the site occupied now by the old county courthouse and city hall annex between Bay Street and the St. Johns River.

After a top-ranked firm emerges for that site, the choice will turn next to whether that is the best spot for a convention center, or if the better location would be near the sports complex as envisioned by Jaguars owner Shad Khan.

Given the cost of a new convention center, the debate also will decide whether Jacksonville stands to reap enough benefits from convention business to justify the steep expense of replacing the Prime Osborn Convention Center, which tourism officials say is too small to compete with other cities.

Other cities have used new convention centers to drive downtown development and job growth by attracting visitors who spend money at hotels and restaurants during their stays.

The three-member evaluation committee is comprised of Downtown Investment Authority CEO Aundra Wallace, DIA board member Oliver Barakat, and city Public Works Director John Pappas. They limited their comments Tuesday to fact-finding questions during the presentations and did not tip their hands on how they will rank the three development teams.

In a sign of the interest in the outcome, the development team lead by Jacobs flooded the meeting room with more than 30 people from the different companies that have banded together on that proposal. The sleek presentation by Jacobs included computer-animated videos that showed off renderings of the buildings with people walking through them while classical music and a chorus soared to a crescendo in the background.

Jacobs put the cost of building its proposal at $598 million. The developers would foot the upfront cost for the construction and manage the facility. The city would pay a total of $1.2 billion over 25 years. The city also would be on the hook for any operating losses, as well as potentially sharing in any profits.

Jacobs' partners on its development team include Westmont Hospitality Group, which owns the Hyatt Regency Jacksonville Riverfront hotel that stands next to the site where the new convention center would be built.

The development team of Rimrock Devlin and DeBartolo Development pegged the cost of building its plan at $450 million. Like Jacobs, the Rimrock team would finance the up-front cost and then seek $936 million in city payments over 30 years. The Rimrock team would design and build the convention center but it would not operate it, so that responsibility and expense would go to the city.

Even as the Rimrock team is seeking to get the nod for its concept, the group already is on record saying the better location would be at the sports complex where Rimrock and DeBartolo are ready to join forces with Khan on building a new convention center and hotel.

The third team seeking the right to build at the site of the old county courthouse is lead by Preston Hollow Capital. It put forward a $458 million proposal in which the city would finance half of the cost. The presentation did not have any figures for how much the city would pay over an extended period of time to fulfill its side of the deal, so that will require coming up with the cost to compare it with the expense of other proposals.

During Jacobs' presentation, the development team contended the main reason that Jacobs has the highest construction cost is because it has enough space for a "fully functional convention center" while the two other proposals have a shortage of space to meet that standard.