Here's an example, found in three or so mouse clicks:

http://www.oldsoftware.com/floppy_disks.html#anchor270200

~ $0.60 per disk is not a superb deal, but it ain't bad.

I'm sure you can find even better deals after more mouse clicks.

Btw, where are you located (you may wish to put that info in your profile)? If you're not far from an MLA member, you'd likely be able to get a few disks pretty quickly and cheaply.