[stigmata]

Some ballpark figures of what should be achiavable for a strong player at each limit:

Microlimits: 3+ is feasible, perhaps more? Rake is obviously the limiting factor here.

Small/Mid_Stakes (e.g 3-6 to 15-30) more like 2-3 for a good player, 4+ has been achieved at 5/10 6-max over the long term, although the recent rake increases probably make this somewhat more difficult than it once was. As you move up through these stakes, the decrease in rake/increase in skill balance somewhat, so similar rates are achievable.

High Stakes (30-60 up) many good players seem to be around 1, although with good table selection I'm sure they can be beaten for more.