The IBM PC was announced to the world on 12 August 1981, helping drive a revolution in home and office computing.In 2006 dollars, that's a $3500 computer, folks.
The PC came in three versions; the cheapest of which was a $1,565 home computer.
That's enough to buy you a nicely equipped Mac Pro with Apple Cinema Display (and yes, I've been pricing them lately.)
On the other hand, the modern-day, common-as-dirt $500 Dell and HP desktops, not as nice as the Mac Pro by a long shot but light-years ahead of the original IBM PC, would have cost $233 in 1981 dollars.
Anyway, the BBC has a very nice slideshow on the history of personal computing, and it's nice to think about one thing that consistently gets much more powerful and much less expensive over time: the personal computer.
BBC News | In pictures: IBM PC anniversary, Birth of the PC