Thank you for sharing your experiences :)
From the Awesome Self-hosted list here check under E-Commerce
https://github.com/awesome-selfhosted/awesome-selfhosted?tab=readme-ov-file
Payment processor, or marketplace?
Payment processing is a lot of work with compliance. That’s one reason that it’s centralized.
https://alternativeto.net/software/shopify/?license=opensource&platform=self-hosted
I don’t have any experience here personally, but alternativeto.net always has good starting points.
Thanks, of course I know alternativeto. Maybe it isn’t clear enough in my post, but what I really want is to read about first-hand experiences with such tools: how easy or difficult is the setup really? Do you really host it yourself or use a VPS and why? What are some potential gotchas? And so on.