Just ebay or mercari for me. Used fb back in the day but….its fb. To get a close to accurate price go by ebay sold auction prices. I tend to mark mine up a little and wait to see what the market does while gaining interest in what i have. I always do best offer too just bc i like making deals. Keep in mind both ebay and mercari charge fees. Ebay is like 10%. Not sure about mercari but when u put a price in they calculate it for you before u list. It helps to know package details too. Size and weight will help determine how much to charge for shipping. I dont sell alot of tfs and don’t look to make a killing off of anything. As long as i can break even on a figure im swapping out or am just not that into im usually good. Have taken losses too but it depends alot on how long ive had whatever it is. If its something ive been able to enjoy and it played its part until something better came along then i dont mind. Take lots of pics and give as many details as possible and of course pack the livin hell out of whatever it is. U dont want to have to deal with returns.