This is a difficult question to answer, as there are many factors to consider when setting a price for your used panties. The most important factor is the demand for your particular type of panty - if you have a lot of people asking to buy your panties, you can charge a higher price. Other factors include the condition of the panties (whether they're new or used), the material they're made from (cotton or silk, for example), and how long you've been wearing them.
Generally speaking, prices for used panties on Reddit range from $5 to $50, depending on all of the above factors. However, some sellers have been known to charge much more - even up to $100 - for their wares! If you're just starting out selling your panties on Reddit, it's probably best to start at the lower end of the price range and see how things go.