EP Shop Trade Ins or New Ways to get EP

I was thinking just now in-game, when something drops from a Rare Chest that is sold in the EP Shop for ex: A Purple Sprite, or Pure Def. What if you could bring that to the EP Shop and sell it for half the EP it's worth in the shop. 

Boss The Kid also suggested to trade in Combo Points for EP, how much EP exactly would have to be determined. 

Yredelemnul & Taiki suggested a Diamond Plated Chest that just drops EP Points.

I like all of those ideas except the trading in combo points for EP.. maybe be able to buy EP for 50k-100k each?

Love it, i haven't received 50k-100k combo points yet, unless you mean money if thats the case i'd suggest making it a bit more. EP is supposed to be tougher to get so i'd say like... 1 mil if it was money but 1 mil for how many EP i dunno Like the ideas though.