A few minor synergies does not push it from $2 to $3. Those synergies aren't even that good. DA usually would not draw nearly as well as Crossroads, and in the cases it would, you'll only be drawing more junk. Cellar can discard it all and draw... again, more junk. Madman can draw more junk. Chapel can trash all the junk, and then DA's draw is useless again.
Your version doesn't really solve any of those problems. Playing a bunch of Ruins for free is kind of interesting, but I think it would be way too much work to pull off and the reward isn't even that great.
In general, I feel that it just isn't fun for a card to reward you for having junk in your hand. Crossroads is fine because you DO want Victory cards, but DA is looking for cards you explicitly want to get rid of.
Alright, I'm convinced it should be a $2, not a $3. But I do think BMan has a good card idea. I like how it would work on boards with Curses/Ruins and lacking efficient trashers.
I also like cheap sources of +Buy -- maybe it's just me, but it feels like most of the games I've played recently have only one source of +Buy, and it's usually on a card that is of only minimal value otherwise, but the +Buy makes it vital card.
Cheap, non-terminal +Buy mean this would get purchased in most of the kingdoms it appears in. Sure, it's not a card that anyone will build a strategy on in most games, but it seems like a good supporting player, and for boards with a lot of junk, it would help cycle the junk more quickly and get to good cards without risking any terminal collision. I also really like the idea of activating Ruins for free.
For comparison, it's probably worth comparing it to the four official $2 cards that can provide +1 Buy:
Pawn -- Choose two: +1 Card; +1 Action; +1 Buy; +$1. (The choices must be different.)
Herbalist -- +1 Buy; +$1 | When you discard this from play, you may put one of your Treasures from play on top of your deck.
Hamlet -- +1 Card; +1 Action | You may discard a card; if you do, +1 Action. | You may discard a card; if you do, +1 Buy.
Candlestick Maker -- +1 Action. +1 Buy. Take a Coin token.
Let's consider a board without curses or ruins; Dark Arts is simply +1 Action, +1 Buy, +$1.
Pawn -- In that case, it's sometimes better than Pawn, sometimes worse, since it gets 3/4 of Pawns choices, but there is no flexibility.
Herbalist -- Since it's non-terminal, it's better than Herbalist in engine games, possibly worse in BM games, but in BM+ games, you probably want some other terminal more than you want this.
Hamlet -- Hard to compare to Hamlet, since they work so differently -- which one you would want would clearly be a case of "depends on the kingdom," but it would usually be Hamlet.
Candlestick Maker -- This is the closet comparison. In kingdoms without Curses or Ruins, CM is strictly better. However, in Kingdoms with CM and DA appearing together, I think DA might still be bought; the extra buys from CM would make a 3-pile ending, wiping CM, Dark Arts and something else (Duchies?) a decent rush strategy.
So as-is, it looks like, without any curse/ruin consideration, Dark Arts would be a middle-of-the-road $2 card. With Curses and/or Ruins, DA can end up functioning as some other hyper-Pawn, depending on what's in hand.
I think the most interesting effects would be gaining Curses/Ruins into your hand when attacked. It helps offset the suffering of being attacked by guaranteeing your next turn is improved by receiving the curse.
Again, I'm not saying it's a power card, but I think it's got potential as an interesting card, especially in Dark Ages games. One of the things I wished existed in Dark Ages is a card that auto-activates Ruins. Ideally, it would be a card that also handed out or gained Ruins, to guarantee Ruins were part of the board. If I have any great ideas in that development space, I'll post them.
