I think $4, and not based on thinking if it's better than village or not. The thing is that when you want this, you want a lot of this, more so than with village I think (except for BM decks, in which case it doesn't matter anyway. The only real difference between 3 and 4 usually is how hard it is to get 2 or maybe even 3 on a single turn. I just think that 3 makes it a little too easy to get a whole bunch if these.
So if this allowed you to turn in a token for an action at any time during your turn, would it maybe be a $5? I wonder if that would be a more insteresting card, because as it is, there's a fair amount of swingyness in which you might turn in a few tokens before playing smithy, and then get screwed on here draw.