as in projector onto the wall, projector?
well i've had a bit of experience with them, nearly got one a while back for a couple of grand.
mrs has one at her place..
i love it, the cheaper they are usually the less lumens or whatever it has, which is pretty much, the less lumens the darker the room has to be. her dads got it set up so it takes up a good 3/4m x 2m on a whitish cream wall, they didn't buy any screens for it.
We always used to borrow the projector from a mates dad, for state of origin and games nights, and would just use a large white sheet.
Only reason that really stopped me from buying it was that the replacement bulb was about 800 or so dollars. And the life of the bulb meant that I'd only be using it everynow and then.. And not leaving it on all the time.
I think her dad paid about.. 2,500..
The ones we used at work which were really good quality are about 6k.
Depends whether your willing to sit in the dark and get some curtains etc. If thats the case then you could probably go cheaper and get a less brighter one