I don't do eBay. I'm just not interested in the hassle AT ALL! For most of my stuff, I use a consignment shop (that's where the Bottega went) and I don't know their price for a few days. They are good and will alter a price if I think its too high or too low -- usually, I don't care and just want to get rid of the thing. They usually price their stuff at between 75% to 50% of retail for stuff in good shape but that has clearly been used. I then get half of what they get. Its not a great return if you are looking for an investment but if its between tossing the thing, giving it to the cleaning lady or getting $250 back on a $1k bag, I'll take the $250.
I did just sell a bag last week through
www.jemznjewels.com. Rachel, who runs the site, isn't always the most responsive in answering queries and emails but I gave her "I used it for one week" Paddington Hobo. She's selling it at retail ($1,500) and I got $1,000. Again, a loss for me but I'm recouping some money that I shouldn't have spent in the first place!
The percent of purchase price you get tends to have more to do with the rarity of the bag than with the original price or the condition, I think. Who cares the quality if its a Kate Spade at a resale shop? You can buy them for reasonable amounts of money anywhere. If someone had a barely used Spy for retail or close to it, its more enticing.
Noriko, I'll let you know when they price my Bottega. But remember, mine is a few years old, a bit dingy and is a Spring color. Resale shops tend to do most of their business in the current season. Winter is what is selling now.