The learning curve in selling online is really steep(steeper and harder for some then others markets) From SEO to photography to everything else and I wont claim some mastery of any... but it feels like there is a perception difference in how you look at selling.
Any and all guides, Dont have some magical ta da secret info you cant find for free somewhere else.
So you have a choice...do the leg work yourself, or have someone lay it all out for you if you pay $.
BUT either way, You still need to switch up how your looking at things and thats the hard part.