Easiest way to solve this problem is just to make it easier for ppl to become stronger faster. Streamline the lvling system so all the hard grinding is done at lvl 108-115+987435464 whatever lvls there are now.
Sell upgrades more often, upgrade rings too. I suggested a long time ago to make a summon event for the element bosses because twin auras are a good cheap cost effective ring. Basically make these kills riskier by making more ppl able to fight.
But hey in a rohan-esque world everybody should have deep pockets already 1/2 of the population is selling organs the other 1/2 are selling themselves.