Closing off the month with these:
Genesis:
Dr. Robotnik's Mean Bean Machine (cart only) - $2.50
PlayStation:
2 Xtreme (complete, GH) - 50 cents
PS2:
Marvel Ultimate Alliance (complete) - birthday gift from BobaFettHotep
DS:
The Rub Rabbits! (complete) - $4.99
I also passed 1500 total games and acquired over 100 this month alone (thanks mostly to the Portland Retro Gaming Expo on the 20th).