I like this idea, the author describes how to use a grinder and convert it into a disk sanding table. I have seen grinders go for under $10 at Harbor Freight ($15 full price). Toss in a disk for another $10 for a total of $20. A sanding disk table can run easy $100. If you combine this with the converting a belt sander into a stand. you can have a $150 combo unit for allot less.
http://www.instructables.com/id/Angle-Grinder-As-A-Disk-Sander/