Not exactly free. First, you actually have to have
on hand to use it, which is a (small, admittedly) difference than having it read "0: Gain 2
...". Second, it's burning off HP of the creature to do so. It may have too much starting HP for that, though. Maybe 3|3 / 4|4...there's plenty of HP boosting stuff out there if you want to use it for turn after turn.