You have to remember from 97 to 2001 we were doubling CPU speed about every year. from 233mhz or so to 1ghz rapidly. I remember getting Pentium 2 boxes at 200, then 333, then 400, p3 at 500 and it felt like a year later 700mhz onward to 1ghz.
add to that ram prices were dropping rapidly and PC cost too I believe so it's plausible you could easily find second hand machines from business or families upgrading - as a kid I got a bunch of $25 computers to build my first home lab with shortly after this time and ran Linux routing since before we had the gem of a wrt54g most routers were crap.
add to that ram prices were dropping rapidly and PC cost too I believe so it's plausible you could easily find second hand machines from business or families upgrading - as a kid I got a bunch of $25 computers to build my first home lab with shortly after this time and ran Linux routing since before we had the gem of a wrt54g most routers were crap.