Seriously, a card is yours when you buy it? What about Trader?
It stops being yours if Trader is revealed.
According to the rules, you gain a card after buying it. So, this means i can (for a very short time) own cards in the supply? This feels very unintuitive, to not say "implausible". Also, Donald lists passing, returning and trashing an Estate to make it stop being yours, none of which can be applied to a card you didn't gain before. Why? Obviously because he thinks about gained cards, himself. Looks a lot like this was another "I felt people would think it works this way, so it works this way" ruling. And this makes me sad, because i always kind of admired how Dominion got along without hard-coded interactions - you could always just apply logic to get to the official ruling. I don't see this with Inheritance (or ist older brother BoM), for a lot of interactions.
I think of buying a card like ordering something online. It's yours as soon as you pay for it, but it's not in your possession until it is delivered, which is when you have gained it.
Hmm... I think this is how ownership in the lagel sense works. Maybe you're right. Then again, i'm curious as to what Trader does. Cancel my order?
Hmm... well canceling the order isn't right, because you don't get your money back. I guess it's like calling up the company and trying to cancel your order. They say "sorry, we have a strict no refunds policy." You demand to speak with a manager. Eventually you get through to someone who says "we just really can't refund your money, but if you really don't want the item any more, then we won't bother shipping it out. And as our way of apologizing for being unable to refund your money, we'll send you a nice piece of silver instead."
Over at Purple Junk LLC: "Why do people keep trying to cancel their orders? "
"We've even heard reports that many costumers are using a rival company's product to throw out ours as soon as it arrives!"