With designer handbags, it is important to realise that the original price paid for a bag doesn't necessarily have much bearing on the resale value of the item. This is why it is important to do your research into what the resale price of a particular bag is currently. Some styles and designs can pass out of fashion. If something looks a bit dated, it won't command the highest resale value - regardless of what you originally paid for it. Remember though that fashions change. Something that isn't particularly on trend one year but well be again in a few years.
Certain styles and brands will resell for higher than the original retail price. Others do retain their initial price pretty well too. It's all down to the popularity of a brand, its design - and even the season.
The importance of photographs
Never just use stock images or photographs taken from brand or retailer websites. Take photos of the actual item you are selling. Ensure that the photographs are good quality, sharp and in-focus, and shot in well-lit conditions. It's always best to take the photographs in a position that is close to natural light.
Know the brand you are selling
You will probably be well aware of this as you bought the designer bag in the first place, but all top brand uses particular signifiers that experienced shoppers will look out for as signs of authenticity.
The devil really is in the detail. From tags to stitching to stamps, there are all sorts of ways that the brands do this. Make sure that these signifiers are clearly shown in the photos you put in your listing online.
If you aren't sure, information about the key authenticators for all the major brands can be easily found online.