I've decided to get rid of my recently bought DLSR kit. I gave it a try and was happy with the results but I really want to be travelling a lot lighter, and to be honest lugging it about is taking the fun out of taking pictures a bit. I want to sell my Canon 15 - 85 IS, but don't know what to ask for it. Going by Amazon prices (used) there seems to be a huge difference of between 300 - 400 quid. Any pointers?