It seems to me that you did the right thing. I believe a seller is obliged to sell the item for the price stated, even if the price is wrong. When it is the other way around, you have to do some obvious mistake, like bidding $2000 instead of $20.00, then promptly inform the seller. *
I had a similar experience. A new seller sold Eau Sauvage with no reserve. In fact, he auctioned all his items with no reserve. After I won the item for $10, he refused to sell it to me, because he "did not mean to" put it out without a reserve. It might have been an honest misunderstanding, but several others reported him too, and he soon became an ex-e-bayer. The professional thing to do for a seller is to just take the loss and thus keep their honor (and customers).