Only focusing on your second part: When I buy I try to find value in all the crevices. I don't just look at stock settings for example. My buying window is open, and I have three options (unless GTX 680 comes out, but I don't think it will) and they are GTX 580 or HD 7950/70, if time permits, a fourth option of the GTX 670 Ti. Anyways, with Overclocking the card is easily 40-50% faster in specific scenarios. And I buy mostly for games I play, which BF3 isn't one of them since I sucked ass and just hid in a corner.)
Coming from a 5870, that is almost 100% improvement and tess heavy games, I saw 200% improvements (Batman: AC.)
I paid $500 for my HD 5870 2GB Eye6 at launch. It offered something no card on the market had - 6 display output. Something I needed for an experiment (which paid off nicely.) Value is subjective, which is why I personally laugh when people try to argue it. Price is definite, we can argue price, but value. I dunno. I don't think many of you would have found the value I did in my card, but then again, I don't know how many of you wanted to run 6 displays, in three different rooms from one PC. I'm so torn on my next card because I want to keep at least 5 displays hooked up, only one card offers that right now.