Dev's price, he works on this game nonestop, monthly updates, Solo dev(he is the artist and the developer).
for a fair reason, the game is not just an image scroller like others, this one actually have a gameplay that is Pretty well praised.
Plus its incredibly replayable, it has a rebirth system, NewGame+ just like DarkSouls, you get to carry your stuff and EXP(reset stats, depend if you died or escaped the land) Thus leading you to attempt and get new different story sides and endings.