For around $330 you can get a GTX 780 which is almost the fastest Nvidia card available.
The Radeon R9 280 will come under-budget at around $210-$230 but doesn't really match up to the GTX 780. There's also the R9 285 for around $250 which is slightly more comparable to Nvidia's example but still slower.
...and finally, if you're willing to save a little extra, you can future proof yourself a tiny bit more by going with a Nvidia GTX 970 (about $350) which should see you smiling for at least 2 years or more.