large parking stucture

I was called yesterday to quote a very large parking stucture
7 floors 760 parking spaces.
I am meeting with the person in charge of maintence for the above today
$8.00 to $20.00 per parking space
3 to 5 cents per sq. ft.
How do these prices look to you?
I have not attempted a job this big before.
Any advise would be very helpful.
I have a 16ft. box truck, with a Hydroblaster5/3000GOVS pressure washer.

Thanks Lady S.

1) Where is the waste water going?
2)Is water available?, every floor?
3) your box truck is probably not going to fit in the garage, going to need lots of hose
4) They looking for a "cleaning" or a "rinsing" ?

Did you get the contract?