I sell on eBay and do understand that it can be anoying to deal with. Than again there are no alternatives that compare. About the only other options is to post on watch forums and you can sell via Amazon but I hear that is not the greatest either.
Ebay and Paypal are the 1000LBS gorilla and have knocked out any competition.
now aside from that what condition are the watches in and are they all Timex?