GeForce 9750? What? I think you have your cards mixed up. Maybe you meant an AMD Radeon HD 7750?
GPU prices decrease a bit from launch to a year or two afterwards. The price then stabilizes. After a couple more years (3-4 total) you may be able to find that graphics card for a more reasonable price.
The 5850 for example. At launch, it was £200. I don't know about the rather purgatory time from 2009 to 2011, but in late 2012-present day, the 5850 can be gotten for £60 on Ebay.
Web retailers, however, will charge anywhere from £100-£200 because it's older tech.
Graphic cards focus on a Price : Performance ratio, and it appears to be refreshed every four or five years from what I have researched.
CPUs that are above £70 in their prime time, usually fall to £70. The Core 2 Duo E6700 costs £70, the Phenom II x4 965 BE costs £70, the Pentium D costs £70 (These prices are obtained from my regular tech retail sites). So don't expect CPUs to come down in price that much. Especially on the intel side.
The Core 2 Quad Q6600 costs around £120-£130, despite it being significantly weaker than, say, the 965 BE.
tl;dr: Sometimes yes, usually no.