If you are looking for a relatively cheap computer for basic tasks  (e.g., Internet, email, or Word), this organization refurbishes PCs and other computer equipment and sell in their “Thrift Store.” It’s all quite reasonably priced, and they are open Tuesdays to Saturdays from 11-6.

This information might be helpful to pass along to your students.

The only thing is that they install Linux on all their PCs, so users would have to get used to using Linux. Alternatively, they sell refurbished Mac computers.

Here is their website:

http://www.freegeekvancouver.org/