Demon Hunter
- best gold farmer (recommend using for farming)

Barbarian
- in inferno all beginner tanks end up tanking or dying.
- to build a good decent dps tank, requires a whole lot of gold then most players have ....

Wizard
- dps not as good as dh ?

Monk
- monk has more affixes to get compared to barb because ... in order to reach all res cap, monks neeed all res + one other res e.g. fire, cold etc ... so that is

vit, dex, all res, one more other res type. these are the cores, and it's not even counting high base armor, +armor, crit dmg, crit chance ....

Barbs are easier at getting all res capped, compared to monk. So i don't agree that monk is any cheaper or easier to gear out compared to a barb.
witch doctor
- best survivability, simply because of his spirit walk which can be enabled on auto if you set the rune modifier which turns it on automatically if you get landed a death blow.
- the creeps you spawn are totally useless in inferno.