We do allot of shows with work( John Deere) and I would recommend Dell. Small and compact, yet very bright and gives great image quality. I particulary like it due to small size. Worth a look though.
Dell is a crap projection company (sorry) - other than price, they offer very poor service and don't support the product long term. They bid out for projectors to the lowest manufacturers, and unlike their computers which use industry standard parts, they don't maintain drawings, schematics, or parts lists which can be used by local repair shops for service.
They are one of very few projection companies which offer such poor quality of service and would be very low on my list of recommended manufacturers.
BenQ does a bit better as does Optoma, Infocus, and Sanyo. Sanyo would likely be much further up on my list as they are a business specific manufacturer with projectors running upwards of $50,000 to under $1,000 so they really know the game of business projection.
Epson also has some good units, but they don't have the top tier models, or anything approaching what Sanyo has, so they don't get nearly the trickle down quality that Sanyo can deliver, but since Epson develops the LCD chip sets which Sanyo uses, it's not like Epson is an idiot - they just focus on cheaper models, and they do it well.
Seriously, for $2,500 I would try to go with a triple projection setup for trade shows so you are immersing yourself into a complete landscape of projection marketing quality. You would need screens and three laptops/presentations to run things, but it would be far more immersive for your customers than the typical projection booth for sure. Probably something short throw (not super short, just short)...
http://www.projectorcentral.com/projectors.cfm?g=1&hide=0&mfg=&p=&w=&r=3&br=&ll=&t=&db=&dt=&c=&ar=&dvi=&sp=14&td=&i=d&is=
The BenQ for example...
http://www.projectorcentral.com/BenQ-MP525_ST.htm
...can deliver a 80" diagonal from about 6-7 feet from the screen and will put up over 100 lumens per square foot which is blisteringly bright - perfect for eye-popping snap to grab the attention of others.
At about $700 it lets you get 3 projectors, and still have money left over for three screens...
http://www.htdepot.com/Focupix_Standard_Portable_Compact_Screen_80_p/fp43ax-80.htm
Perhaps going a bit over budget - but that would be crazy impressive at most trade shows that I've seen.
