@Patrick Gleason - for a 35 unit building, this seems extremely low. If you were going to PM an apartment building, you would typically see 8% of rents and that's just to answer calls, collect rents, and deal with minor issues like lockouts.
What they are asking you to do has a lot more involved and would require legal services on your side, time, recordkeeping, and tax prep.
$960 a month for this is nothing, especially in Boston. You should find out what they are currently paying their current PM. Or find out what others typically pay.
For such a large building, you might look to only collect 5% of what gross rents would be (yes, they are condos, but what would they rent for?)
You need to present them with your schedule of fees. You can certainly have a minimum charge (I would say 2 hours, not 4). And your management fee would include something like 10% on top of labor and materials for any work (so if a repair costs $100, you charge $110 and keep the 10 as your management fee to coordinate the repair).
This is my opinion of what I've heard and I don't do PM in Boston but know others who have a PM for a similarly sized condo association. Anyone who has actual experience as a PM would have better info for you. I think you would be losing money by taking 960 a month for that many units.