How to build your own stool (cheaply):
Go to lowes or home depot and get a 8 to 14 inch pre cut wood circle. (Wood or pb or mdf, whatever)
Now go to the pre-carved wood section. There should be table legs, lazy susan brackets (for swivel chairs), feet and anything else you might need. They might even have banister spokes, which are great as they have a dowel shaped butt on the end of them.
If they have it, get a sheet of foam padding. It doesn't really matter how thick it is as you can always double up.
Ok get stain or paint while your there and next head over to your local fabric or furniture store. Pick up some cheap vinyl, you'll only need about a yard tops.
Take yoru precut circle and set it on your foam tracing the outline. Make as many circles as you want until you have enough padding. Keep in mind that you'll compress it slightly.
Drill any holes for spokes or mount your lazy susan to your circle, and then place the foam on what will be the top of your seat. Now staple your vinyl over the foam and onto the bottom of your circle. Trim as you go, place well, and use a LOT of staples.
You should be done. If you wish to stain the legs do so.
That's a simplified version of the process obviously, but my point is building a stool is nothing compared to building a cabinet. So I say go for it!