What is my authetic Knoll barcelona chair set worth  

I would studiously avoid any Ebay seller operating out of
"Dealtown, USA".

Thanks for commenting, I...
Thanks for commenting, I will consider updating the profile. Whats your opinion on the value of the chairs located in erie pa?

Those pictures
I was looking at a Barcelona on ebay last week and saw those same pictures on a different auction.
Were you asking like $10k last time?

Once can't possibly venture a guess
from the single small photo you posted. You allude to damages, but don't SHOW them. You allude to maker's marks, but don't SHOW them. You invite people to stop by and see them, but don't give directions to Dealtown, USA.
The secondhand value of damaged furniture is highly subjective, there's no Bluebook-value. What people will pay is what they're "worth", literally.
You're not giving a potential buyer a lot to go on.

I hope someone wasn't using...
I hope someone wasn't using my pictures without my knowledge. There is another selling offering similar chairs (better condition than mine) for 20K. Do you think this a reasonable retail price for vintage chairs?
Link removed by DesignAddict: Please don't advertise your eBay listings on the forum. Thanks.

Perhaps you're simply trying to advertise your auction
to a likely group of potential buyers, by posting here?

I guess I need to get a camer...
I guess I need to get a camera with better focus, the 5th row from the top, picture on the left is the best picture of the stamp I could get with my camera, the stamp is somewhat faint.

Oops, sorry-
found more photos at the end.

I think its nuts to post your...
I think its nuts to post your full name and address on the internet, I am more than willing to provide my contact information via pm or email. In regards to my intent, I am simply trying to determine a fair value for these chairs.

Businesses post their contact info all the time--
it's just a straight-forward way to do business. How are you in danger by posting your city and state? Why make a buyer jump through hoops to find out if you're 3,000 miles away?
A buyer has to make a leap of faith to send you thousands of dollars, but you won't post your address?

Yes, a business location is a...
Yes, a business location is a different story, but if the location is your home its not a smart idea. I dont consider an email asking for my contact information much of a hoop.

I tried updating the listing ...
I tried updating the listing information with my zip code, but since there are bids I cannot make changes to the listing.

Value varies
I'd expect that a decent pair of Barcelona chairs would bring between $3000 and $5000 ($1500 to $2500 each). That is the price I'd estimate from a reputable dealer or auction house, maybe a good seller on eBay who has a good reputation, is knowledgeable what they are selling, and has presented good clear photos and a detailed condition report. Obviously a pair in excellent condition are worth more.
I think that price range is very fair if you consider that new Knoll production cost $4328 each, $6609 if you get them with stainless steel frames. I happen to like a nice vintage patina and some light wear to the leather. Kinda' broken in, but not tired or beat.
If there are serious condition issues, the price will go down obviously. Restoring vintage Barcelona chairs is expensive. While they may look simple, they are very labor intensive. New cushions are going to cost $1000 per chair in good leather. A set of straps will set you back $600. So if you are looking at a worn out set, you are essentially buying the frames and you should budget $1500 per chair minimum for new straps and cushions. If you are quoted significantly less, I'd question the quality of the leather or workmanship.
rrdr, from the photos in your auction, it looks like your chairs need new cushions and possibly new straps, they look like they are stretched and saging, dry and beginning to crack. They may be able to be tightened, conditioned, cleaned up and colored. You'd have to replace any that have broken, or are about to break, but it's possible that you may be able to avoid getting a complete new set. In the current condition, I'd expect those to bring between $1000-$3000 ($500 to $1500 per chair). Good luck with your auction.

Thank you for a great post, I...
Thank you for a great post, I appreciate your feedback.