Interesting embargo-variant card. It will change openings because of the "setup" part.
Like embargo, sometimes it might hurt yourself more than your opponent.
Suppose you open 5/2 with sea hag on the board. Your opponent opens 3/4.
Buy Sea Hag on T1, pay 1 debt and Tax Sea Hag on T2.
Your opponent now have to spend $6 to buy that Hag!! (if he does not buy it on his T1)
I played one game of Tax, and there was no +Buy. Under those conditions, the top part of the event wasn't very useful. It was only bought a few times when people had really dud turns. And it didn't actually do anything, because we often overdrew our money and could immediately payoff the debt. I think Tax would be much more useful with +Buy.
I agree. However with +Buy it would be strong enough to cost $3 instead.