Problem with one time mows: Generally the customer can't afford lawn care.
Can't afford to fix or buy a new mower.
Can't physically do the work any more due to age and with age reduced income so they can't afford lawn care.
See lawn care as work for the brain dead, brain damaged, or brainless and it kills them to pay anything above minimum wage for it.
What is good about one time mows
Is that it has allowed landscapers to make extra money at double or triple rate because of the extra labor needed.
Many LCO's have picked up good accounts.
Nothing ventured nothing gained. Does every time a estimate call result in a new customer?
Does every one time mow end in a bad experience?
And if handled right it will pay well.