Hmm...good question. It was ten years ago, and my memory isn't that good.
I used five sheets of Luan to cover the front and back. Last I checked, it's like $8 a sheet. If I had to do it again, I would not have covered the rear. It adds strength, but adds weight. When I flip it up it's like doing stand-up bench presses. To cover the front would require three sheets for my 140" screen (10' wide), but if you had a more reasonable size, you could do it with two sheets...so lets say $20 for Luan.
The skeleton was 1"x4" pine. It's been a while since I've bought that, so (guessing) the price for a 10' section would be $15? If I rememmber correctly, it used five pieces, so that would be about $75.
A gallon of KilzII is $15.
I had the hinges, but I guess you could pick the up for $10?
$20 - Luan
$75 - Pine 1x4
$15 - Paint
$10 - Hinges
------
$120
That should be pretty close Matt.