@cl-scott, I think the OP's question is rather clear and concise. He's asking about one specific board model (p8z77v deluxe), not about series variations.
I'm sure this is still as much the case now as it was in the past. Board revisions come out as certain bugs/issues are resolved on a hardware level that cannot be fixed via bios update. Or perhaps some change in manufacturing process or component supplier.
Granted, a low volume reseller maybe selling customer returns as new to be able to afford lower prices. Best to always check the return policy, pay with a credit card, and do your research about the vendor if something sounds too good to be true.
Rev # under the white pcie slot, immediately to the right of the model #. Mine says 1.02 too, bought ~3 weeks ago. Obviously not just one revision. Not sure if v1.00 or 1.01 ever made it to market.