Well, since you have a simple setup, the cost would go down a little.

I'm going to guess you'd prefer a widescreen projector. Good projectors would range anywhere from $1,500 to $3,250 (USD, of course). These would be your higher-resolution projectors, being at or around 1280 x 720, which is a great resolution (around 720p, maybe?). Remember, the lower the resolution, the more distorted or "fuzzy/blurry" the image gets when projected at higher sizes.

Also, most of those projectors would be HD-compatible. Meaning, of course, that you could hook up a high-def signal to it (in one form or another).

Anyone care to correct/amend my suggestions?