I combined the Dorm Desk and Flip-down Children's art desk plans to make a perfect combination for my school work.
The Dorm Desk was designed to be used with bar stools, so it would be rather tall. I simply made the dimensions shorter to fit with a computer chair. I also tweaked the children's art desk a bit for use as a laptop desk, just took out the shelves and put a piece in to hold binders and whatnot.
Another note, most of the materials used were scraps from other projects, so the dimensions are a little different there too. For instance, I had some 6" strips of 3/4" plywood sitting around, so I used those for the shelves instead of 1x8's, and I used a piece of 1x12 for the front of the wall-mount desk instead of plywood.
The estimate cost is not at all what it would cost if you were starting from scratch. The only things I payed for up front for these two projects was the D-ring hangers for the wall-mount desk, a piece of plywood for he desk top, some tin flashing, and a 2x2 for the frame.
*the tin flashing I got ended up not being magnetic, which was disappointing, but it ended up working well with wet-erase markers (the kind teachers use on overhead projectors) so at least it still has a function. I may also end up puting a cork border around the edges so I can still hang things from there.
Hint: I used an old wallet chain for support on the wall-mount desk. I also found some left over hinges and a small clasp I had bought for a keepsake box I made years ago. If you're pretty handy, you probably have plenty of stuff you can use just lying around the house.