For about $50 you can get an Nvidia GeForce FX5200 256MB AGP.
http://www.newegg.com/Product/Produc...82E16814145083 It doesn't take up much space, has a tiny heatsink and fan so noise won't be a factor, won't drain your power supply, and should be able to handle Sims 2. I think that's the best you can do for that budget.