Several years ago, in anticipation of my son’s wanting a computer, I bought a couple of cheap ($10) Macintosh IIsi systems (the original list price in 1990 was over $3000). Last week I set one of them up. I found a number of cheap childrens’ titles at local used bookstores (for example, “Just Dad and Me” for about $2), and a trip to RE PC in Seattle yielded a copy of System 7.6 for $5.
I’ve had to do a little refurbishment (replace the lithium cell and clean some tin contacts so the speaker would work). But aside from that, the systems are 18+ years old and still working.
One of the bonus effects of using a near-vintage machine is that it’s simply impossible to hook up to the Internet (at least, not without me doing it — there’s no ethernet or modem on the machine, soo…).