The most I ever sold a pair of panties was for .60. panties for cash. Bee-ware though. Have you met the kinda guys who will give that for a pair of your panties? Unless postage is involved, it is not usually worth exposing yourself to that element.
Years ago, I had a friend that was very happy to buy an old pair, and then another... but I think it is a rarity. Oh, and there was one other... .80 once.
maybe your worn panties are more in demand, who knows? *(grin)*