AMD is launching a new $150 mid-range card today called the HD 6790. It performs better than Nvidia's GTX 550 Ti but it ends up trading blows with Nvidia's two GTX 460 models. You are more likely to find the 768MB GTX 460 for around $150, but there are a few open box 1GB GTX 460s at Newegg right now. If you're an AMD purist however, the HD 6790 is what you need to get at this price range.
Here are the XFX and HIS models for your eye holes: