Sorry but we don't really talk values here, as it depends on too many factors. Basic rule for value is "whatever you are willing to sell it for" or "whatever someone is willing to pay". This varies greatly depending on things like condition, where it will be sold, reputation as a seller, how quickly you want the sale, what customers are around at the time, etc. On ebay, it might go for £10, or if you get a couple of bidders fighting over it, it might even go for £40 - £50. If you were to list it at £50 though, you could end up relisting it week after week and not sell it in a year...