According to my guesswork, it would cost nearly 2Mep to upgrade six of everything.
~220 cards (Commons, +36 Rares (12 x weapon, shard, nymph), Relic, + others...)
1500ep/upgrade
220 x 6 (of each) = 1320
1320 x 1500 = 1.98Mep
How can anyone have ground that much wealth? What is the fastest way to earn wealth, expressed in an EP/min ratio? Divide 2000000 by that and tell me how many minutes it takes...
I just don't think its possible