Here's an article from an Australian PC magazine that incorporates computer ads spanning the last 20 years or so. Do you remember when 20MHz was considered FAST
? And Mega (forget Giga or Peta) was a new word in the PC computing lexicon? If so, you will definitely want to check out this article
from Overclockers.com.au (OCAU).
The best stuff is on page two from the 1980s but it wasn't that long ago either when a Pentium 5 machine was all the rage and cost, well, cost a lot! (Granted prices are in Aussie dollars but even if you multiply by today's exchange rate of 0.7 it still ain't cheap.)