If you've spent any time on eBay you may have noticed an item or two offered with a "Buy It Now" options along with an "Or Best Offer" option. Material Girl enjoys making a Best Offer. Just like any negotiation, I usually offer a bit less than I'm actually willing to pay (at least $10-20). My goal generally is to get the item for half of the Buy It Now price. I've watched items be posted, not sell, be reposted with BIN option, not sell, and be posted yet again with OBO option. Sellers who have spent this much time to unload an item and paid multiple listing fees are happy to have interest (and they've probably posted with too high a starting bid). I've never had a Best Offer rejected. Many sellers will accept it outright; others will make a counter offer.
Just last week I offered $60 for a Karl Lagerfeld asymmetrical mocha wool skirt with a $149.99 BIN. The seller counter offered with $75 and I bought the item (at 50% off the BIN, a nice deal for this brand). And the skirt is cool and interesting, the fabric is beautiful, and it fits me perfectly. Skirts are great items to buy online--it's tough to get one that does not fit properly if you are given measurements. I wish online retail store would give measurements as well. One store's size 4 can be another store's size 8. And, with a store like Anthropologie that carries a number of brands, sizing can be all over the place. Stores like the Gap are safer, but even their sizing can change slightly from season to season. I probably have 30-some skirts hanging in my closet and I'd say about half are from eBay.