Most of these "scammers" are really just bad businessmen. Instead of being vague in the description about their content, setting high prices or charging ($9 - $20 for each individual post), they need to focus on getting more loyal returning subscribers. To do that, they need to set reasonable fees, be honest in the description about what type of content they'll be uploading and how frequently they'll be posting. Also engage with fans, and I don't mean just talk money which is what most do. Especially the straight ones.
Charging an entrance fee and then an additional fee(s) to view content the customer initially came for might make the content more desirable, but it will not encourage many to be loyal returning subs. They'll most likely just pay once, screenshot everything, leak it, and cancel the membership. Why keep renewing to pay more? Long term gains vs. Short term gains. Also, respect your customer's hard earned money.