I have both bought and sold socks and jocks before. For me specifically it has less to do with the scent itself and has more to do with the essence of the individual. I have found over the years that a lot of folk like musk, and usually have a certain tolerance for how musky something can be before it is to much. The scent alone does not do anything for me, so much as whose scent it is. This smells like this person and that makes me happy. If it gets to strong to where it is just musky and no longer smells like theirs, then I lose interest in it. Intense scents can still be used for play, but they will always be better when I can distinguish whose scent it is.
As for pricing they can be anywhere from 20$-100$ (+/- shipping). I have personally never spent more then like 35$ or so, but I have sold them for more. When someone would want something specific like being worn for x amount of time or fresh from a day at the gym, you can always spike the price a bit (cum socks too). Some individuals find an appeal in the fact they are paying for it as well, causing them to get off the more they have to pay because it makes them feel even lower, or more humiliated.
Now I have not done this in years, but I do still have a shoe box of socks from friends who have moved away, or live to far away, that I always keep under my bed. They are in individual ziploc bags to try and preserve their smell. There is a particular par of black puma socks that have such a sweet scent to it that I can almost taste it when I sniff them, like I am licking the icing off a slice cake. Another pair of dry-fits have a much more earthy and hefty scent to it. You have to get in real close to catch a whiff, but it hits hard and strong once you do. The nuance and difference in individuals scent profiles