Check out the Recommended Graphics Cards page for Premiere Pro. It is always best to check system requirements first. AE is not picky, but Premiere Pro only has a few display adaptors that will give you Graphics Acceleration.
The NVIDIA GTX 280 is on the list and can be purchased for around $100 from several suppliers. Try a Google search for the card.
The video card you are looking at from Fry's is the GT 520. While it might be fine for AE, for Premiere Pro CS5 or CS5.5 you really want one with 96 cuda cores or more. Do a search on Fry's for the GT 400. You will find several GT 440 by different manufacturers all for under $100.
For Premiere Pro CS5 and CS5.5 you want to have a video card with at least 1 gig of DDR5 memory. Then you can do the unlock or hack to enable Premiere Pro CS5 and CS5.5 to run the Mercury Playback Engine in GPU mode.
If you want to spend a few dollars more look for the GT 545 with DDR5 memory. Do NOT buy a video card with DDR3 memory if you are going to run Premiere Pro with the MPE in GPU mode.
Here is some information about the hack http://www.studio1productions.com/Articles/PremiereCS5.htm
Here's the deal with those cheapo GeForce GPUs:
They (for the most part) have too few CUDA cores and molasses-slow, extremely-low-bandwidth VRAM. And even most GT 440s in the sub-$100 range use slow DDR3 VRAM instead of the more desirable GDDR5 VRAM. Those cheapo GeForce GPUs will make encoding, especially MPEG-2 DVD encoding, with CS5.5 very sluggish (and frequently even slower with MPE GPU acceleration than in MPE software-only mode). This is because those cheapo GPUs simply cannot handle high-quality renders (for example, the MRQ that's automatically utilized by MPE GPU acceleration) without choking. And based on the 300-plus second MPEG-2 DVD encoding result in the PPBM5 benchmark tests with a GT 440 even on a heaviliy overclocked i7-2600K, you're better off going a bit over the $100 limit and opting for the GTX 550 Ti. (The GTX 560+ GPUs are even faster, but they also cost much more.) You get what you pay for, in this case.