The idea was to use a single sheet of hardwood plywood, and some basic hardware to build this desk for between $75 and $100. It could probably be built for less if you changed some of the materials.
Unfortunately I didn't document the build process at all, so I only have pictures from several years after it was built, and some pictures of a much larger version that I built later. I've included pictures of the other desk (a similar design), and the completed desk as it is today.
Step 1: Planning
I laid my desk out on a sheet of graph paper using a 4 squares per inch rule.
Step 2: Planning: Legs
So the height of the legs is measured off of the side of the plywood, and then split in half to form two legs.
Step 3: Planning: Top
The wood left over from this cut is used to provide a backing panel for the desk to strengthen the design.
Finally, how long should it be.
The simple answer is "whatever is left once the leg portion is removed", but you can always shorten it to fit your needs or space. At most this will be around 72"
Once you have the basic measurements, you can calculate how much support wood you'll need as well.
Step 4: Materials
I used 3/4" white hardwood (possibly Maple or Poplar) from "the Big Orange Box", but there are other species available. ($30 - $50 depending upon where you get it, and the species).
You'll need some material for providing support to the desk, and attaching the legs and back to the top.
In my case I used 2 8 foot 2x4s and about 3 foot of 2x2, but you can substitute other dimensions of lumber, or even use hardware for joining the corners.
You will want at least one board for the center support since the plywood will warp at that length without some support (I added mine after building when I realized that it was needed). ($5 - $10)
You'll also need some "wood veneer edge banding" to hide the edge of the plywood once complete. (I think I paid about $30 for a roll, again at the Big Orange Box place).
Screws / glue / finish. I used wood screws, but didn't glue this one. I'd glue it if I did it again. I used a "one step" stain and finish. ($10 -$40 depending upon finish choice).
Step 5: Cutting
They will do one or two for free, and then there is a fee per cut after that ($1?). Unless you change the length of the desk, it should only be 4 cuts so it won't add much to the price, and their panel saw does a great job on these long straight cuts.
Step 6: Assembly: Back
Since this is the back of the desk, and mine will always be against a wall, I just screwed straight through the back plate, and into the corner support. You could screw through from the other side, but you'll have to be careful not to punch through the plywood.
I first attached the backing plate to the corner supports, then attached a full length 2x4 turned on edge to support the desktop.
Step 7: Assembly: Legs
I started by attaching the top supports to the back. These supports will attach the legs to the top.
Next the legs were attached to the side supports with wood screws. I screwed through the outside, very close to the top. These screws can only be seen if you are on the floor looking up, but they could have been filled with wood filler or even run through from the inside.
Step 8: Assembly: Top
Once I had assembled my desk, I realized that the top needed additional support, and added the 2x4 shown in the pictures. If it's planned ahead, it could be done a bit better, but this is functional, and can't be seen unless you crawl under the desk.
Step 9: Finishing
It applies with an iron (the iron heats the glue on the back and attaches it to the wood), and then can be trimmed, sanded, and stained to match the rest of the desk.
The last step is to sand and finish the desk, just like any other wood project.
Step 10: Enjoy!
I hope it helps someone design and build an economical desk.