I am posting from my cell phone so forgive me if there are any errors.
I sold my used panties for years via internet for $50-$100 each. Men WILL buy it. I sold them all the while working as a internet solo xxx model so yes you can make a killing selling them online depending on how you go about it. Some guys will even pay you more to deliver it to them personally (I never did that.) The Used Panty industry is a HUGE one. You can google and see that for yourself. Don't let others discourage you. Please do not sell your panties for less than $50. That is totally selling yourself short and always make the guys pay for shipping.
Most men will want to see a picture of you in the bra and panties. You can create a webpage for $10 a year(blogger) and display your items. You can even offer camshows for $2 a minute and accept payments through Alertpay.com if that is something you want to get into so the guys can see the panties live (you don't have to do anything xxx you can just model them for the guys) You can host your camshows on skype, yahoo, msn.. etc.
You can sell your panties several ways.
Craigslist.org is a good place to start.
Don't even try ebay.. they stopped that kind of business a long time ago.
Ebanned.com is an awesome place to sell your used panties.. hell there are
men there that will even buy your chewed gum and your used bathwater. (It's amazing!)
A friend of mine sold her bikini for $800 there. She has been an online domme for years so she has a good following.. that could be why it went for so high.
www.myusedpantystore.com is a great one.
You will even find men at myfinancialdommespace.com It's social networking for men looking for financial domination/online domination and dommes. I think you will like that website.
I can also send you an ebook that helped me when I first started it. I can send it to your email free.
Anyways, Good luck. Don't forget to post about it on craigslist and backpage and see the response you get first. There are other great sites but I'll post more when I get home. Good luck again.