I no longer do it comaro, because I paid my way through college and now make 6 figures as an Engineering Manager making financial decision for a multi billion dollar corporation....and yes...I still have 6 yards as well as my own (5 acres) that I keep up...not a formula...making a point....chevy HD is not a requirement...
I gross into the 6 figures as well, working a solo op lawn service.
We're not going to break down numbers, because it's nearly impossible to when you're talking business / pleasure.
I'm sure that you're doing the yard work for the tax benefits, if nothing else, so congrats on that.
To say you only need 1 of stuff, what do you do when you're working 60-80 hours / week, and the mower dumps on you?? You just drive to the rental shop and rent one?? Not hardly. You take the other one that's still on the trailer, and get to the shop either when your route takes you there, or after the work is done that day.
I'd be completely HOSED if I only had a setup like yours.
I run a 24' enclosed trailer that holds my main ZTR, my backup ZTR, a 48" walkbehind, 10-30 bags of fertilizer, my PermaGreen spreader, my Echo polesaw, my 2 trimmers, my brush cutter, my split shaft equipment, my 2 backpack blowers, my spare tire, my papertowel rack with GOJO bottle, my 3 bottles of 2 cycle mix, my 3 quarts of different motor oils for the equipment, my battery for the interior and exterior lights AND my garbage can.
My trailer is my portable shop. I can do most anything that a customer asks when I pull up to the location, without having to go rent, or go back to my permanent shop.
Also, it's fully lettered on the sides and back, so when I pull into my commercial places, I look like someone that should be there.