Last month I still had a Pentium 233Mhz in the apartment... heh.
Back when I built that machine, Pentium II had just come out and it was too expensive for me to afford, so I went with the fastest Pentium I. The 450MHz P2-MMX went for like $799 just for the processor alone. I never did end up owning a slot-type CPU, skipped right over them to another socket type.