I didn't find a PC deals topic so I thought I'd start one.
Steam has Mass Effect 2 for $4.99
List of Abandonware sites with PC Games.
Abandonware is software still under Copyright protection, but the owner does not appear to be tracking violations or enforcing the Copyright.
These are generally considered to be "orphan works" where the original owner cannot be contacted for whatever reason.
No attempt has been made to verify any of the software you download from these sites and you do so at your own risk. Scanning for viruses and spyware is highly recommended.