The 486 machines are still in abundance. Many people do not realize that the reason Pentium Pro's are so rare is that they were only made for 3 years, and mainly used in servers. The 486 chips were made for twice as long and used in lots of home computers. Intel was still making 486 chips(non ceramic) for use in embedded systems up until 2007.

You would be amazed at the age of computers people are still using. I picked up a bunch of old compaqs that were just retired from a montessori school last week. They were window's 98 machines with amd ceramic chips in them. I can't imagine they had much fun with them.