Let's not forget the environmental/weather considerations. Granted if there's someone that wants to come push mow an acre or so of my property in the middle of an Alabama summer for free let me know so I can save a few cents (maybe a dollar) on diesel.
Even as a relatively "young" individual (by some standards) I've learned there are some things that just don't make sense to do.
On my place, I've used:
- a push mower which can be dang near deadly in the middle of summer, especially if you're trying to get done in a timely manner (can any one say heatstroke?)
- big-box tractor-looking riding mowers, where I went through enough to learn those didn't hold up to the heat all that well either (even when properly maintained), plus they would get stuck in the ditches where it'd be muddy/swampy until early/mid summer.
- a used zero-turn for a few years as well, did a fairly decent job until it too died (middle of summer) though it would frequently get stuck in the same places as the other small mowers which meant having to mow some areas with a string trimmer (which I wouldn't recommended doing unless conditions force it).
...and so I bought and use my tractor which has already survived more hours of operation on my property than any of the prior mowers (actually it might be getting close to as many hours of use as all it'd predecessors combined). ...which to me implies water-cooled engines and equipment built for durability & reparability will likely be the cheaper option long-term (even if it costs a lot more up front). Part of the reason why I bought the tractor was because all the air-cooled mowers were dying at a rate that it was costing me ~$1000/year (not including time, gas, routine maintenance, or parts) to mow a fraction of my property.
.....oh, and the tractor has yet to get stuck (even when the ditches are wetter/muddier) when mowing anywhere on my property. So as I've said before there are different tools for different situations and methods, and everyone needs to figure out what works best for them in their situation.