I will be aquiring 15 lawns next season due to a friend going off to college. He mowed all 15 lawns with a 21" push and he told me it took him about 30 to 35 minutes to mow the lawns. So i figured okay it will probably take me 20 minutes to mow. Right now my Encore 36" WB is paid off. My John Deere is half way payed off(only paying $160 a month at 1.9%.). Adding these 15 lawns would bump me up to 39 lawns. Is this a time to purchase another mower or should i just keep the same setup of what i havel. I would like to know your guy's input on this. THANKS.