One who has surmounted such levels as Assholery, Grand Fuckerydom, and so on in such a way of varying degrees of Buttholism. A jewchebag is somewhat like a douchebag but is more concerned with monetary ideals than the douche.
N00B-"ZOMG you can't even spend, like, a hundred bucks on our Galaga Reunites tour tickets???"
Goyim-*sheeeennnnnhaaa* "No way dood, I have to deposit ALL my money to the Bank of Moses!"
N00B-"...You are such a jewchebag!!!1!one!!"