I have picked up a few accounts for fert and chemicals last year which now totals about 20 lawns with a cumulative area of about 10 acres. Most of these lawns have obstacles and only get 1-2x fert and 2-3x chemical applications per year. I have managed to cope with a 2-stroke Maruyama backpack sprayer and Shindaiwa spreader for years. But now I am considering investing into something more productive. About what size do you have to total to make a ride-on investment worth while and what equipment would you recommend in my situation?