I do agree with what shovelracer was saying.
Although I feel that your Toro mower should suit you well, if you do happen to get more than 20 accounts you may want to consider the idea of getting a used 60"/72" mower. Just make sure you can make enough money back to still be in your profit area.
Make sure you have spare belts for your mower, good traction on your tires, and all the normal maintenance.
The grass cutting season spans for apprx. 32 weeks of lawn mowing, plan on as little as 25 cuts per lawn due to droughts, unless they are really bad droughts in your area. Some areas may cut for a longer span but that is mostly towards the Southern parts of the country.
You shouldn't go through more than 2 rolls of weed wacker string in a season, assuming you don't go over 30 lawns or have to edge a lot of driveways and sidewalks. Buy 50:1 mix in bulk in the beginning of the season, Echo oil comes in 8 packs of 2.5gal or 1gal mix, im sure it varies more but that's what my supplier carries.
There is an Old Blue Chair for each and every one of us, we just have to find it.
2015 Ram 3500 6.4l hemi 4x4
BOSS 8'2" VXT
Hustler X-one 60" 3 bin bagger
Toro Proline 36" wb w/t-bar controls
Walker S14 36"
Shindaiwa T242, Echo trimmers, chainsaws, pole hedge trimmer, pole saw, hedge trimmer
Shindaiwa 633 and Echo 755