That's what I'm trying to say; affordability is all relative. If I'm in the market for a luxury watch a Tag or a Bell & Ross is affordable. They're still ~£1500, but compared to JLC or Blancpain they're affordable.
Yep.
I feel like my 670 will likely be able to max games out and hold 30fps for at least the first wave of next-gen console ports, but I'm also afraid that if I'm wrong about that, I'll be stuck buying a new card in the middle of the release cycle, and I'll run the risk of spending $500 on a new card only to have another new one come out at the same price a short while later.
If you upgrade as soon as the new cards are available, you're at least guaranteed for a little while to have the latest and greatest thing out.