Hah! It's a really cute idea! I like it!
I think it'll be on the weak side for a curser - players could just discard however many cards they could afford to discard without impacting their buying power this turn, and have a reasonable shot at getting a free pass on the curse. If that's the response, it'll be like a witch that sometimes misses. I'd say it's a little better than Torturer if not stacked, but worse than Torturer if multiples are stacked. Worse than Witch and Mountebank definitely. It's also a little more vulnerable to countering by stuff like Horse Traders, Watchtower, Library, Jack, etc.
But it's still going to be a good card in a lot of situations, and "on the weak side for a curser" still means it's a good card. And the +$2 instead of +2 cards makes it less vulnerable to collisions...
And, of course, the exact power of it is trivial to tweak after playtesting by modifying the distribution on the die! 4/3/3/2/2/2 if you want to power it up, 4/4/4/3/3/2 if it needs a nerf, 4/3/3/3/2/2 for just a slight gain in power... 5/4/3/2/1/0 if you want to make it really swingy and hard to plan for!