As a friend let me say to everyone speculating how it needs to be done-
1. We don't know what is in the contract.
2. It might be a flat monthly price paid over X months.
3. It might be bi-week.
4. The OP hasn't been there to have a serious look at it.
5. I have yet to find a person who can keep up with me on a trimmer for $10/.
6. I have no problem making 3 people run trimmers all day when it has to be done. They cry for an hour and then they get the work done.
7. One 60" mower keeps pace with one hard working trimmer-dude in a cemetery.
8. 100 acre accounts pay over 100K a year. Get in the game-anyone can do this. Have you ever ran a full tank of gas through your ztr without shutting off the deck? There are guys like me who call this a job.