The best way to get an old Mac is a) nearby and b) for free. But if you want pick of the litter, and are willing to part with cash to do so, some will try to fleece you, thinking their obsolete hardware is actually worth something (hint: it’s NOT unless a lot of work is put into it, hence this and other Web sites like it).
But there are places selling used Macs at what look like good prices.
I just came across Computer Geeks.com, which has this page of desktop Macs (Here’s an iMac G3 700 MHz for $189) and this one of laptops. The laptops are a bit pricey, but I’m not really up on what iBooks are going for.
And for those of us in California, Geeks.com is in Oceanside, so that means less $$$$ shipping for locals.
If you are in the market for an iBook G3, Other World Computing has this deal running: iBook G3s from $199 to $359.