Filmmaking / Directing : Location Advice by Reuben Baron

So I have a script that made the quarterfinals in a contest and is very topical, so I'd like to attempt to get it made soon. It seems the logical first step in producing my script independently would be to figure out a budget, but one big question that will affect budget is where I'd be shooting. 80% of the script takes place in a single big location, which typically is a good thing for saving budget. The difficulty is that the location is a convention center during a gaming and fantasy convention, and trying to figure out the best and most affordable way to shoot a convention center is a question. I could try to rent a convention center for the film shoot, but would it even be possible to rent a convention center for the multiple weeks required to shoot the film? If so what would be the cost (I'm in the northeast and would ideally shoot in either Boston or New York)? Building sets wouldn't require the same sort of rental agreements but would be even more expensive. Theoretically I could shoot some scenes guerrilla-style at PAX, which would reduce the need for extras but also means reduced ability to light scenes properly, worse on-set sound, and an increased need for effects (to disguise/replace logos), plus that means limited time and I'd still need to find locations for other convention scenes (for example, the big climax takes place on a stage in the convention center, in which case there'd be no way of filming those scenes during an actual busy con). Anyone have any advice for me on this matter?