I have a 4660 Coupe I bought new for $110000. 1 of the last 10 built.  I spray 7000-10000 acres a year depending on year. Easy to get 700 acres a day doing 5gpa with a tender truck & driver.  about 500 acre a day at higher rates.  I have Autosteer & section control .    I would hate to pay custom rates for this. 
Chemical prices are a lot different from suppliers on cash & carry.
I'd almost bet it would average $5-10  per acre  per pass .  That almost pays for a employee