I worked through Amazon - they had several levels of editing - i paid for it - wasn’t that bad - then used Create Space [ https://www.createspace.com/ ] to bring my book up and start selling on Amazon - it’s self-published and print on demand without fronting a huge cost.
Yes - I fronted my editing - but it needed a proof to make sure all grammar and style was addressed - worth it to me.
What was your opinion of Amazon’s marketing services?