We have been invited to bid on a 50 acre property. Really want to calculate a fair price. Property Manager say it takes 40 man-hours to mow and 40 man-hours to weed-eat. Says they use a Grasshopper Mower. Amount of time seems excessive as it is rather straight mowing and trimming. We use 60 and 72 Turf Tigers. My question....what do you standardly charge per acre (including trimming) ?