i73770k: But they're not good cards anymore. They each only have 1GB of VRAM (SLI does not make it effectively 2GB), use a lot of power, and even in SLI, you might as well spend your money on a better single card. If you're going to bother with SLI, you might as well just invest in a single better model, like a 760GTX, so that you can upgrade later to 2x.
It's good that ru124t seems to have some realistic expectations about what these cards are (not) worth, but it'll still be difficult to find some takers. Those just cards don't fit into a useful niche. On their own, the cards aren't pretty low-performance and antiquated; together, you'd need to SLI them, but you might as well invest in something better (a single card even) if you want to bother.
Those cards are certainly not worth $200 each anymore like shown in that Amazon ad. They're only that price because only a few shops still happen to have that card on a shelf. Both cards together might be worth the $200, but even it's probably worth just spending that on a low-end modern card.
Who knows though, maybe a few diodes sitting around are worth the price for the pair?