This is a very basic and relatively plain desk that I made myself because I strongly dislike desks made out of mdf or anything not solid wood, because of their inability to be reformed, added onto and their knack of falling apart so easily. Most of what I found on craigslist or in stores was made this way. If it was solid wood, it was most often overly ornamental and decorative or simply too large or not in a finish I liked, or the worst of them all: expensive.
This desk's final price came to just under $100 I believe. The work that went into it is not beyond the reach of most people, and it can easily be modified with extra components to fit personal needs and/or wants.
It's design had 3 requirements to meet my wants: 1) A solid wood surface with plenty of room to do homework on 2) with a curve cut out of the front so one can situate themselves "in" the desk while working at it. 3) a raised shelf for an external monitor. 4) be easy to disassemble for transport. 5) be under $100.
Step 1: Tools
Here is a list of tools and stuff that I used. If you have a band saw, by all means use that if you want. If you want/have other legs or shelf risers, those will work just fine.
60, 120, 220, 400 grit sand papers
0000 Steel Wool
Table saw - with ripping blade if you have it. If not a circular saw will do
Jig saw - with a SHARP blade...mine was terribly dull
3/8" or ½" roundover edge bit
¼" cove bit (optional, I didn't use because it was $16 more)
*First, mark the line you want to cut. Then measure the distance from the blade of your saw to the edge of the shoe. Clamp the guide rail/wood that distance from the line to cut. Then keep the shoe butted up against the rail while you make the cut. Provided your guide rail is perfectly strait, your cut should be too.
3 cans Minwax Satin(or whatever gloss you want) Finish spray Polyurethane ($6 at Walmart)
4 legs http://www.ikea.com/us/en/catalog/products/10105290
2 shelf risers http://www.ikea.com/us/en/catalog/products/40051196