dondon, thanks very much for the ideas! I have to say that I think removing the self-trashing portion of Boycott makes a lot of sense. I think I've got enough one-shots in the set without it at this point. I also really like the idea of making the pile that the token starts on a $5 card. I might test it with and without that part. I wonder if moving the Boycott token should be optional for the version that doesn't trash itself.
So how does this version look?
BoycottTypes: Action
Cost: $4
+$2. You may move the Boycott marker to a nonempty Kingdom card pile in the Supply.
Setup: Add an extra Kingdom card pile costing 5 Coins to the Supply and put the Boycott marker on it. A pile with the Boycott marker is not part of the Supply.
At this point, I definitely don't want the gained Boycott to go on your deck, since I want all players to be able to buy a copy of Boycott before it gets removed from the Supply. Not that you were necessarily advocating that in combination with the removal of the self-trashing clause. I just thought I'd address it.
EDIT 2: I also glossed over the concern for Clerk's power in countering Scrying Pool decks. An alternative suggestion is to set aside Clerk and trash exactly 1 card from your hand upon getting attacked instead of trashing any number of cards. This still turns discard attacks into a net benefit and also soft counter Curse-givers but not to an extreme extent. I just think that being able to trash your entire hand in response to an attack is really swingy. Compare to Trader, where revealing it in response to a Curse-giver is not so amazing.
Hmm, I understand your concern. There are two reasons I haven't changed Clerk's reaction to [set aside/trash one] as you suggest. First, it would have to be a lot more wordy and I'm worried about space on the physical card. Second, I haven't actually had balance issues with Clerk's current reaction. As I've said, it discourages buying Attacks on turns 1 and 2. After that, the chance that you're trashing more than 1 or 2 cards from your hand is pretty slim. I mean sure, you might get lucky and be able to trash 4 Curses, but you might also be able to buy 8 Provinces by turn 13 using Chancellor. The odds just aren't in your favor.
As far as countering Scrying Pool decks specifically, I'm not really concerned about interactions with a single card (see Mill Town/Tactician) unless they create rules ambiguities, are able to shut a player out of the game, or are absurdly powerful combos that you can build without relying on your opponents. If Clerk's presence means players don't buy Scrying Pool, so be it. There are plenty of games where Scrying Pool is dominant. If Clerk turns out to be too powerful against all, most, or even a large proportion of Attacks, I'll definitely change it. I'm definitely open to the possibility that it's too powerful and I just haven't playtested it enough yet. It certainly does
look powerful, I'll grant you.