I guess I’m not understanding why you don’t think of your facebook business page as your portfolio. Is it not a body of work presented to potential clients? Sure, you may have a printed portfolio, but this is not what most people will see, as most marketing is done online these days (as you said- your page is for marketing purposes.). Therefore, I would prune your fb page back and get rid of about 95% of what you have presented. They aren’t very good- for a variety of reasons that have already been mentioned- bad/unflattering posing, bad lighting, dated studio backgrounds, lack of creativity, among others. And as for just striving to be a bit better than your competition, that sounds like you’re setting your sites pretty low. As of right now, I would suggest not charging at all and just shoot for the joy of shooting (and learn along the way- yes, even if you have decades of experience- which isn’t evident in your work)
And my qualifications for critiquing your work- hobbiest, about 4 years experience, never have made a dime with any of my work, and don’t plan to for quite some time, if ever. And if you think that discounts my suggestions, that’s completely fine.