Karma - Gold
the problem is that karma is easier to come by then gold since you need gold all the time but karma is just sitting there, even if it was 10.000 karma per silver i just know there are players out there that drown with karma and can simply make a huge profit from it.
that, and karma becomes yet another currency players farm for, i would rather see some stuff like cultural armor and such have a way to buy trough karma so you always have an alternative for such things.