Originally Posted by greenstarlawns
Look at buying a commercial Honda, Exmark, or Toro 21" mower to get started and then step up to a 36" hydro unit when you can pay cash for it. This will let you learn the business and your properties before spending alot of money. Unless you already have a trailer and you only plan on staying with residental get a 6*12 trailer, it may seem large at first but you will grow into it, also get it with a sigle 5,200lb axle or a pair of 3,500lb axles. This will come in handy if you do any install work or mulch delivery.
I would buy a larger mower than this for sure unless you are doing the tiniest lawns. You will never make it to the point that you can buy a bigger mower because if you got any 20,000 square foot lawns or even 10,000 square foot(roughly a quarter acre) you will make so little money per hour doing it that you will quit. You cannot be competitive with a 21. I would go with a minimum 36 but I would recommend a 48.