whenever I am in this situation I always think about whether I can buy the two items, keep the one i'm interested in, and sell the other for a considerable price, so actually sometimes even obtaining an item for a profit, or at worst, for a small, reasonable price.
If you can sell the tool itself for ~£30 - £35, then the cheath will end up costing you £2 - £7, and you never know, might get lucky if you put it on an ebay auction, get a couple of enthusiasts who happen to be after this tool right now bidding it up to a much higher price. Take some nice pics, put up a very nice description and review, I always finds that does wonders.
I normally also write on that I am open to buy it now offers, sometimes you can get someone offering you a very good price right from the start of the auction. Thats how I managed to sell my luxeon 3watt LED torch for £20, actually more then I bought my Stanley tripod 3AA torch for.