I price based on yardage, fiber, and weight. Finer yarns are a little more than bulkies, plied yarns are more than singles.
You don't have to have an exact pricing structure. You're making it and you can set the prices. When I started figuring out my prices, I looked at popular sellers who were spinning yarns similar in style to mine. Basic, pretty, workable yarns, and then figured out their prices per yard. After that, I figured my price per ounce and tripled it to see if I was getting enough back.
Things that I feel are not my best get a 10-20% discount.
Don't compare ANYTHING you make to commercial goods. It's not the same, and you are not expected to compete with those prices. You are catering to a different audience than those who are expecting a $35 scarf from Dillard's.
Part of the problem for determining prices is that I tend to think "well, what would I pay for this?" My appraisal comes out shockingly low, because I wouldn't pay for it. I'd make it myself. You're not pricing for makers, or for those who don't understand the value of your time. Be mindful of that when you're doing your math.