Ah, thanks for the clarification on the screen, that makes sense. I assume the screen has some structure to it, almost like a lenticular lens on an RPTV, that directs the light back to the viewer and so the closer to straight on the better. I wonder how far off you can be. I'd rather not have the screen too high and I'd like the projector high enough to be out of people's way. Although with the rear seating near the back wall I guess I could put the shelf at 6' or 7' high and it won't be in the way of anyone. The room is 10' high, with a vault down to 8' on most walls, so that does affect placement of the screen.
As far as the cost, it's a bit of a mixed bag. I paid for a media wiring bundle in my contract, and for the cost of that I'm getting a lot, a total of 25 drops split between coax and ethernet, as well as wiring for two surround sound setups and stereo to the patio, plus the projector and a few other bits and pieces, and security wiring. But adding stuff ala carte is expensive. Also, they run 16ga speaker wire and CAT5e. To upgrade to CAT6 they want $1,000! But they said I could supply them 500' of speaker wire and 1000' of CAT6 and they'll use my cable. They don't discount for using my cable, but they are running additional speaker runs for the theater.
I could possibly run some stuff myself. My salesman says that's not allowed, but perhaps the builder will have a different view on that. However I know I better not try to run my own electrical in a place where it might stand out. And I really don't want to have a lot of extra wallplates for stuff I'll never use.