I will say that local vendors will NOT come out to your place to show you a $5,000 projector that they earn $300 on due to the proliferation of Internet pricing. Some places will come out to large venues with high dollar projectors and setups, but I can say that it is extremely rare when a commercial place will do so for one room. If the goal is to watch your cash, then take the square footage of the screen, multiply it by 80 lumens, then buy a projector with AT LEAST that many lumens.
Take the numbers and run it through the Projector Central calculator, linked above, and see what results you get.