I may not understand the way the card works, but it appears that for $3 you can trash a card and gain a card for 2 more than the one trashed. When I clicked on the card, though, it did not give me any options for trashing, gaining, anything. It just ended my turn, I did have two cards left in my hand. Game #37262741 on Oregon. Thank you.
Probably those 2 cards were Estates, which being Victory Cards you can't trash with Enhance.
I assume Markus is right. Unfortunately, the game ID you gave is from another game (does not contain Enhance).