@SamDuranta I don't know what you're trying to sell, but I'm afraid your practical understanding of who uses push mowers, and how much they use them, - thus, the inputs for your "math" are completely bogus.
I see that you conveniently ignored the math that I posted previously, about my experience, and cost of comparing
my own cordless string trimmer, vs. 2-cycle gas.
Let me sum it up with a quick story - I haven't used the cordless string trimmer in over a year - despite having more than enough batteries now.
(Well, in theory anyway...)
Now, in the string trimmer example, all the battery has to do is spin the cutter-head & string.
Vs. a self-propelled push mower, that has to push that mower through tall spring growth, even on un-level ground, then generate enough airflow to pull the grass into the deck, and then cut/mulch/discharge those clippings.
If you really want to convince this crowd
(and whomever your targeted "customer base" is ...) that cordless mowers are better, I'm afraid you'll have to put your money where your mouth is, and go generate more income with the cordless push mower, than is possible with a gas-powered push mower. Before you start down that very epensive & painstaking road, let me warn you, that it will be an economic loser.