As CR says, $200k per player for your bench and then send them to AAA.
For your bullpen, I'll agree with pinotfan, in that there are too many variables. What kind of rotation and the quality, the ballpark, etc... But in general I don't spend much on my bullpen. There are two other recent threads which discuss constructing a pitching staff for $80m and discussing the value of your bench versus your bullpen. I think you'll find both I these helpful.