It is never our circumstances but our mindset that holds us back. Lack of funds has never held back the determined and dedicated writers that I know personally.
Style comes from a lot of writing + reading a lot of well-written books. As Rebecca pointed out, “Bad writing is not a style. Word choice and how a writer structures their prose is part of it.”
I think there should be transparency in such things. I don’t like to hear of newbies being scammed. Knowledge is power and should be shared. Fairness is important, and I would hope that, as a community, we value those who do a good job for us.
Strictly speaking, true betas are just casual readers, preferably your ideal reader (someone who enjoys the genre/subgenre that you’re writing in). Many will disappear, never to be seen again, if the story is not in an almost finished state.
A developmental editor should be able to give feedback just by looking at the first three chapters. They will be able to identify any lapse in logic, under-developed scenes and characters.
Just as proofreading is the absolute last chance to catch things before publication, self-editing is the absolute last chance to catch things before someone other than you gets to read your story for the first time.