You'll be hard pressed to get a PJ setup for under $300 to $400 total even if you are 'cheaping' out, anything less just isn't worth it, get a TV instead.
Don't want to disappoint you, but it's not worth the cost of the lamps or the parts that would need to be replaced.
It's 1024x768 resolution.
Generally, to repair projectors (unless it's something simple), you need to have some pretty advanced electrical diagnostic skills, or an identical working model to go by.
You can get a refurbished Benq th670 for $350 and it will include the lamp, and it has a warranty.
Otherwise, look for a used Optoma hd20 or similar model on Ebay, you can find them under $250 sometimes.
Also used Viewsonics (but riskier as you have to know what your buying), or used Acers (again risky).
For a projector screen, you can make a homemade screen by tacking Blackout Cloth to the wall (it's white not black).
This will cost you $20 to $30, and it will look just as good as a $500 screen. You will want to eventually frame it with some black material though.