I just sort of eyeball it now but, if it helps, here's where I am on my two "still in regular season" teams:
509 DUR, 613 STM MG
389 DUR, 809 STM Coop
The quality of the pitcher really matters. A 25/70 isn't the same if one guy is a 1.35/4.05 WHIP/ERA guy and the other is 1.07/2.89 guy. Also, keep in mind that you don't need to make the entire season with that staff. You get the A/S break for recovery and roster expansion.