Had to look this game up, never heard of it. Is that a dev set price or a player set price? In my limited research, it seems like that's a player set/community price for a game that seems to be dying.Hex tcg cards can be resold just like artifacts and the packs are around a buck too IIRC.
While I believe the dev set price is $4 in MtGO, boosters can go for below/above that on 3rd party market places, depending on the expected value of a pack of a certain set (much like physical MtG boosters). Artifact will probably be the same way, assuming boosters will be eligible to be put on the Steam marketplace (i.e. the price will be below $2 if players only get an average of $1 worth of cards out of a pack, which is why I said the singles market will be much, much more important than the dev set price of a booster)