Three things that hardly matter for thousands. You can still boil water and simmer with the cheap stove. My parents stove is probably well over two decades old and never needed a repair for anything. I imagine a techician will have an easier time repairing a basic gas range where all the parts are generic compared to getting the miele certified mechanic out or whatever.

People who are just boiling water and simmering probably aren't buying the expensive stove, tho.

more BTU: BTU on a gas stove is ridiculous — they are so lossy that the flame pattern is a bigger deal.

better simmer control: even a lot of expensive gas stoves have fairly bad simmer

repairability: I regrettably own a fancy Thermador stove that is hard to repair — extracting the crappy ignition units requires a special tool that has been discontinued.

If you want excellent temperature control, get a Breville Control Freak. It outperforms everything else (generally by far), it’s offensively expensive at $1500, and it’s also cheap at $1500 if you think of it as the best stove that just happens to have only one burner.

You’ll also discover that 1800W (~6100 BTU/hr) is about right for most purposes with pans up to 12-14" at near 100% efficiency. You do not want 15000 BTU/hr delivered to your pan for any purpose other than boiling water or maybe reducing a big stock if you are stirring actively.

> You do not want 15000 BTU/hr delivered to your pan for any purpose other than boiling water

Wok afficionados may differ with you here. I get by on 10k BTU/hr.