Generally, it's considered bad form to use the APUG classifieds to advertise eBay auctions, at least in the first post of a new thread. In the future, a more accepted way of using the classifieds as to post an ad so that people can purchase the item from you directly without going through eBay, and then if it doesn't sell after a reasonable interval (what is "reasonable" depends on the item, but usually a week or so), you can move it to auction and post the link as a comment in the existing thread, not as a new thread. Note that it is not considered inappropriate, from APUG's perspective, to advertise simultaneously on other forums like RFF, LFPF, photo.net, etc.