Ok, I don't know the prices, but here we go:
Free:
AvP (traded away)
Orange Box (traded away)
Valve Complete Pack (traded away)
Tropico Trilogy (traded away)
X3: Gold (kept)
DOTA2 (traded away)
L4D GOTY (traded away)
SPAZ (traded away)
Sniper: Ghost Warrior + all DLC (traded away)
AaaaaAAAaaaaaaaAAAaa!!! A Reckless Disregard for Gravity (gave away)
Cthulhu Saves the World + Breath of Death VII (gave away)
Bought:
Audiosurf
Rock of Ages
Demolition Inc
Fable: The Lost Chapters
AaaaaAAAaaaaaaaAAAaa!!! For the Awesome
Fate of the World
Foreign Legion: Buckets of Blood