Not enough transactions to form a positive PC. Last known person I can think of to buy such item was YOU. At 55e. Don't even know if there is much demand for this although it is a very nice skin. Personally I'd like to know myself what the potential value of said item would be too.
Just put it on high end and let it run......I can guarantee you that you'll get offers high enough for it to be there, but as for a cap, I don't want to put a number on an item not sold very often. Just see what people are interested in.