Why do heroes cost 900 gems now???

Hi, I really enjoy the game, but took a break for a few weeks and noticed that the heroes now cost 900 gems. Is that supposed to be normal? Do they stay at this price or is that temporary? I was at 280 gems and on my way to unlock my second hero, but 900 gems is impossible to aquire. This will take me months. Does anybody know if this change is permanent? If so that would be disgusting by the devs...