We have a 20 acre property with a mile of curbs defining parking and the west border. Since my decks trim curbs as we mow, there is minimal trimming as I sterilize a 3 inch band around all hydrants, phone boxes, poles, etc. We complete the job (Mowing and trimming) with 3 mowers in 1hr. 50 minutes and charge $500. According to my figures, that is about $83/hr.
Efficiency = Profit