It is a card which looks brilliant in theory. Trash a Copper and instead of Moneylender's terminal Gold or Spice Merchant's Lab you get a Hunting Grounds effect.
But you don't want a Hunting Grounds early on, you want Moneylender's payload or Spice Merchant's cycling. Without Cursed Gold, i.e. Pooka as an ordinary Kingdom card unrelated to a particular Heirloom, it would probably be an OKish $5.