We got a lot of work done cheap with two different pull type sprayers, most of that with the most expensive tractor on the front being a 5488.

Off the top of my head, I think $2/acre would cover every check we have ever written for our current SP sprayer purchased used in 2015.   That includes a full set of Michelin SprayBib pizza cutters plus two Michelin 650 floaters (when we purchased machine it had two almost new Michelin 650s and two Goodforayear, one of those came apart on the road at 32 mph and we gave it a full matching set of good shoes) plus a wheel motor failure.   That's not including fuel, an operator, or the labor/truck to tend it when farther away from the tanks at home, but it's also not including the fact that there's a paid for machine in the barn that would auction for a pretty high % of what we paid for it in today's  environment.