I am super on the fence about Booster Packs in general, because most modern booster pack based trading cards are just gambling.
I've worked around that by making the cards in these packs all equally common/rare, so that there can't really be chase cards.
(and, of course, by being a small game that does not have an existing secondary market, so that even if some cards were rarer than others, there's no dollar value associated with the rarer cards, removing the scratch-off mentality.)