Just came up in a game I was playing:
If on my turn I overpay for a Doctor and as part of resolving the overpay ability I reveal and decide to trash an Overgrown Estate, do I get +1 Card immediately, even if I still have to resolve more cards for the Doctor overpay, and put it into my hand? Or do I wait until I'm done resolving the overpay before drawing?
I also assume that I can't actually ever do anything with that card that I drew? If it's an Action, I can't play it since I'm in the buy phase, if it's a Treasure I can't use it since I can't lay down more Treasure after I've started buying cards.
Or... wait, I suppose if it's a Market Square I can gain a Gold with its reaction ability? Are there any other cards I could draw that I could possibly use in that situation?