See, that's me. If I decide to buy one, I'd have it for my own use and all those costs would be on me no matter what. If I can get $50 a mow, that's $50 I wouldn't have had other wise whether it goes to the machine payment, fuel or the beer kitty.
But aside from the liability issue, I also have to keep in mind the 'legally required' reporting options for such 'income'. We all do that, right? (Wink, wink, nudge, nudge!) So what if I run over the bed of freshly planted Petunias and the friendly neighbor lady decides to call the Tax Man? Yes, I have considerable stock in a Tin Foil Hat company.