whom are you guessing against? do you know what this contract has gone for in the past?
There are a lot of tricks for managing Turf this big, the number one rule is you don't need to trim every week (or every visit in your case)
Why is the Football field dormant but not the rest of the turf? What's it look like in season?
Is that the field they are managing on their own so you don't have to do it (because they are cutting it with a reel mower)
You also have to look at the RFP (request for proposal) are they requiring you to pick up or manage trash that might be on the turf?
Why are you going to mulch twice? Because they asked you to, or you just figured you would? Are they asking you to trim shrubs three times or is that you saying you are going to?
Normally I would say a single mulching and two shrub trims would be fine.
What are is this property in? North Carolina? Or somewhere in the mid west?
Judging from when you thought you would be cutting Im assuming south.
You act like your costs are high, that doesn't make sense to me. If it's just you, what do you think are your costs? the truth is you don't know.
There are good tools to figure it out, however you aren't truly going to know until after your first year, at a minimum, but you can project costs and then try to stick to a budget.
What other contracts might you have, besides this school, if you get it.
Something this size would warrant and employee.
You will need good mowers too, I would suggest something like an exmark, dixie chopper, bad boy or hustler, ones that aim at big big turf.
I wouldnt make equipment purchases until you have properties already sold, unless you already have equipment.
because if you dont get something like this, you aren't going to want two WAMS on your trailer to do aunt marthas lawn.
I can teach you what you need to know on the basic level as far as how to project your costs and establish a budget, which will tell you around where you need to be charging for an hourly rate, Im also sure there are plenty of other guys who would too, trick is finding someone to mentor you who is willing to do so for free.
It's not the easiest thing to do over an online forum.