I like the idea.
This is somewhat nice early on for the non-action trashing, but actually stacking them to good effect seems difficult. You need a lot of drawing to have enough to trash to make them worth something. Definitely not strong enough to be worth $5, maybe not too strong to be $3. If you open with 2 of them, you do trash pretty rapidly, but can't buy anything.
If you want to make it stronger, maybe if you made it just worth $2 if you trashed at least 1 card. That makes it really strong at the start -- probably one of the strongest openings, but with a single one will fizzle out later on, since you only have so many Estates to trash, and if you trash a Copper with it, it's almost just like playing Loan. So it's a solid $4 opener for an engine, and maybe even BM. But then it can stack much more strongly, since you only need to trash a single card to make them all worth $2. While $2 doesn't sound like it should blow anyone away, the fact that massing them allowed you to trash down to just your drawing card and a handful of these makes it probably decently strong. Needs playtesting though. If the massing style of play turns out to be always better that the single one trashing into engine then it will end up being a pretty boring card.