I'm going to resist the temptation to be humorous and actually offer you some value.

It's been a while, however the used pantie market in the USA, unlike in Japan tends to be centered around CAM girls.
Prices tend to run from $20 to $60 depending upon how enamored your target audience is and what your personal market will bare.  The traditional methodology is to provide your sales pitch, photos of you in your panties with the ubiquitous wet spots on your website with online sales form. The  technical key being once you've elicited a sexual-emotional response you need to close the sale immediately, thus the form must be a single click away for instant processing.

Personally, ( I recognize you didn't ask ) I think it would be in-congruent with your current marketing (on your current website). In many respects it would be like Tavern on the Green installing a drive thru ( or bike thru) and offering hamburgers.  In any client base you will find a few individuals who may engage in a purchase however be mindful of the difference between anecdotal evidence and a measurable, replicable trend.

You may find a useful article here http://goo.gl/HqwdA7

 
I hope I was of some help.

 
Lee Dreams  
Edamus, bibamus, gaudeamus  

Damn typo edit.

-- Modified on 8/1/2013 12:27:48 PM

on very reputable fetish sites. It's a lot easier than you think!

PM me and I can help point you in the right direction! It's a great way to make extra cash from home :]

I'll sell you mine for $10.75 plus S&H I take payment through PalPal. PM for PayPal instructions.

A provider I knew needed to move out of her apartment, so I moved all her stuff to my house, supposedly temporarily. Then she retired. I had 2 trunkful of lingerie including panties and, because she was doing fine financially and didn't need to work, the lingerie was of high quality.

I tempted to sell the collection as dirty lingerie. I would wear bras and panties around the house and then package them. For authenticity I would include a strand of pubic hair. I would hope that the buyer don't run a DNA test.

That was five years ago. Recently I gave most of it away. I might have a few lying around.

A dear friend of mine picks up panties after every swinger party!  First he posts to our guest list as "lost and found" and then if no one claims them, he sells them on ebay!  He makes up delicious and decadent stories (some quite true) about the panties previous owner and makes an amazing profit!  go figure

I used to sell....

7 years ago I used to sell my worn panties
This was in the era of Craigslist, so either responding to or placing ads in the erotic services section.
"Sweaty summer city cyclist's soaked panties....."
"Sweet bi-sexual college student's flirty white panties"
LOL...it was fun writing the ads for them.

Generally, the buyer would want me to have worn them for several days, to have masturbated wearing them, not wiped after going pee.....etc. Most buyers wanted the panties very "thick" with that feminine scent.  
The panties that were requested most were cotton briefs. basic. classic.  
I asked for $100 per pair of 3-day worn panties.  
I would package them in a little envelope with a bow....so the buyer felt they were opening a gift! I had many repeat buyers because of it.

You figure out what panty fetish is worth to you, how much interaction you want to have with buyer if any, and you price accordingly with demand