I wish to suggest,if the market system is added, have an npc to exchange lives/chance cubes/reward bags. I might elaborate more once i get back on the computer as phone is quite hard to use.
I feel anything to exchange something such as chance iaochedrons for a full heart would be a wonderful idea. Perhaps something at spawn like the signs on SF2?
some people have already found out a way to get 200+ hearts with very little quest book progression... 3 teams with 200+ hearts and around 5% complete.