Nice Coin Wrong Size And Weight

I wouldn't ask for a discount; I'd either return it if I was unhappy with the price paid for what I got (and you have every right to be unhappy here, the coin was clearly misrepresented) or keep it if I would have paid that price for the coin had I known what it was.

I think the coin is a bit overpriced for an As in this condition. I have purchased very attractive sestertii of Hadrian for around $75. But it does seem to have an interesting reverse (Hadrian standing ?). Perhaps better pics may shed light on whether it can be 'improved' a bit.

"If" the coin can be cleaned up is the $49.99 question !

As a buyer I would want a discount, but I am also a seller so if I made that mistake I would just ask the buyer to return it, but at my cost, and refund them all their money. Unless the mistake was in their favor and it was worth more than naturally good for them and the buyer should keep it. If someone is selling hundreds of coins, mistakes can be made, hopefully caught before hand. I have had sellers misidentify coins as Constantius when their were Julian and so forth. By asking for a discount you obviously still want the coin, and customer satisfaction is important. However, discounts should be applied before hand. I once sold my old Iphone and the Buyer found that while the phone was exactly what they wanted I had accidentally mislabeled the serial number by one digit. So they held me hostage for $50 bucks and I had to give it to them, as they refused to return it and just wanted to extort money. So being on both ends I tend to agree with other posters that you either return it at no cost to you, or keep it. I know you decided to ask the seller for a discount, which as a buyer I am tempted to do, but if the seller is someone you want to do business with it may sour them towards dealing with you in the future.