My total came out at about 200 bucks using Pine 1x's from my local lumber store. I used some stain to bring the grain out, and topped it with a couple of coats of Helmsman.
The only trouble I had was with getting the cross members in right. I put the front one in backward.
The second support back from the cab didn't line up with the frame support holes. About an inch off. Hmmmm. Can't figure out why. The holes in the bed line up with the holes in the strips... Weird. Anybody else run into that? Aren't the supports symetrical?

CJ