I am new to PC gaming (not online yet). I am upgrading my 256MB graphics card so that I can play Assassin's Creed II. I was looking at the Evga E-Geforce 8800 GT 512MB on eBay currently for $40.00. It this a good choice for the price today (2014). I am definitely on a $40.00 - $60.00 budget here!
More about :evga geforce 8800 512mb good choice today 2014
A new nVidia GT 640 is just about in your budget and will run on most power supplies and will match your CPU pretty well. If you want to find a used card, first make sure it will fit and can run on your power supply then test it either in your system or the sellers to make sure it's stable in games. Radeon 7750 is a good budget card to look for used, a Radeon 7770 is even better and you can probably find a used one for $50 or so.