http://www.htdepot.com/Focupix_Widescreen_Fixed_Frame_Screen_105_p/ff169lt-100gy.htm
This is by far one of the best screens you will be able to get for the money. Your budget is really (really!) low, so a fixed on-wall grey screen is likely your best way to go.
The Focupix isn't as good as a lot of other brands, but it's way less money, and it's easily the best at the price which I have seen.
I'm not sure what you mean by 'man cave'.
A projector ideally goes into a home theater, but since that isn't always possible any room with controlled light will work. Controlled light being the key. Dark paint on the walls and ceilings can be added to any room. Dark carpet is tougher, but is a good consideration.
Controlled lighting is the first step in the process to home projection nivana.