I'm curious too. I have some diy skills. A projector has never really been on my radar. I think I'd have to close every blind and curtain to get it dark enough in my living room.
I think I got the Epson 2045, 20' HDMI, ceiling mount and spare lamp for $700 +/- a few bucks. I chose the Epson over a similar Optoma due to lamp price.
Sherwin Williams paint ain't cheap, I think $70 gallon. Pro classic Enamel Satin Finish - the minor sheen it provides equates to screen gain which will improve blacks.
You'll need a 3M Fine/extra fine sanding sponge, plastic tarps and the surprisingly expensive Frogtape. Make no mistake, normal masking tape won't keep the paint out!
You need a foam roller, which they didn't have on display in the 9inch size. But a conversation about my Rick and Morty T-shirt kept the rollers from being charged, FYI. Primer and putty to flatten any and all drywall seams, holes, whatever. Drywall sanding screens if you don't have your own pro sanders. Then you need good even pressure and a keen eye to keep the surface flat with out beading from the roller's edge. I dilute the enamel with water, just spritzing to increase viscosity. You don't want it runny, but the right amount of water will help more with the self leveling nature. I reuse Windex bottles for spraying water (I wet sand furniture I build so this is routine for me) and you'll sand between coats.
Lots and lots of sanding between coats. You'll see with enough moisture the paint will start to loosen and become liquid-y again, don't keep spraying, just spread and smooth with the sanding sponge. Let it set for a moment and then roll on another coat.
If you're still reading and interested, great! But this is a lot of work and does not necessarily save money over Amazon projection screens. Because this is our living room, I was intending to provide a clean look that does not give away an obvious projection screen with black masking. So it is more than worth it to me to put in the effort. However, you are at the mercy of drying times so you can only recoat at most every 90-120 mins or a water based paint will peel.
