How much could I sell my Radeon 2400 for?

I bought an ATI Radeon HD 2400 Pro graphics card this year at CompUSA's going out of business sale for my computer. However it is AGP, and I upgraded my system to PCI Express. The card is in good, working condition. I only used it for about 5 months. I have everything that came with it except the box. If I bought it for about $80.00, how much do you think I could sell it for?