The days of mining with your personal computers are over, unless you want your hardware to be toast for no reward.It is simply not worth the effort.Even many Graphic cards are obsolete.
Ooh. Can you recommend the cheapest mining set up one can own. I really want to go into this mining thing. Seems I'm years behind.
Why not buy a single GPU to start mining? just put it in your PCIE to your PC and you can start mining.
And I would like to share you one of the good thread where you can find which GPU you should buy that can make you real profit.
Check this here
https://bitcointalk.org/index.php?topic=5135665