Inverters have gotten a lot more capable and quite cheap; you should take a second look. Also look up "soft starters", they're devices designed to reduce start current on motors. They get mostly used for solar and generator A/C, but would work with a well pump, and might put it in the range of your current inverter.
Speaking as someone who has had to run a gasoline generator to pump well water and is about to move it to solar, with great rejoicing.
!! oh wow, they actually support the full open-circuit voltage that my panels can be series linked* to reach! the only thing i saw many years ago was like... the power wall!
Not only that, it can run every panel i currently own all by itself. that is a leap forward, compared to the last time i checked (a decade ago or so, it was depressing to want a separate solar grid, you need the grid tie stuff so you can run your house if the power goes out, but i mostly wanted the solar to manage water and lights and if possible, the small window/wall aircons that i use to keep servers cool.
Speaking as someone who has had to run a gasoline generator to pump well water and is about to move it to solar, with great rejoicing.