I eventually learned the best model (for me) was to copy what Yoast did… charge a flat free for SEO Audits. People were always super happy with my audits. I still have my SEO audit templates (one for local SEO, national SEO, etc). Sometimes it would only take me 4 hours to write an audit and I would get $750, sometimes more if they wanted a more thorough audit. Maybe I undercharged?
If you want to make real money with affiliate marketing, then set aside the idea that it is a get-rich-quick scheme. Affiliate marketing will only lead to immediate riches if you cheat and that, eventually, can lead to fines or jail time. If you want to make money at affiliate marketing and sustain that income over the years, then you have to do it right and that takes time.