Monks are better bots for the sheer cost. A monk comparetively cost compared to a Barb is no contest. You cna gear a monk for 20-40 million that will out kill/mf/gf a 300m geared barb. However, if you have an sload of loot, like me, barbarians have the best kill speed/mf/gf.
If you get banned on a barb tho, it hurts a HELL of a lot more than a monk. My barb probably has 1-1.5 billion in gear.
So the moral of the story is, if your worried about getting banned, or are just starting, the monk is a very close 2nd to barb, and probably theoverall better choice.