> Radeon HD6970 outperforms an HD7750, and earlier cards like the HD5750
> are not far behind the 7750, while they can be had at a fraction of the cost.

Current best price on eBay Germany for used card:

HD 5750: 33 EUR (= 35 USD)
HD 6970: 99 EUR (= 104 USD)
HD 7750: 25 EUR (= 26 USD)