I believe a lot of the prices are down to the Whitman type folders that RM released for the modern 50p. All easy coins to get ,except the 2009 Kew . I know the feeling of needing to fill a gap , so can understand people wanting to pay over the odds to do it. The 1992/93 EEC 50p only had a circulation of 109,000 ( I remember them in my change when I was in my teens ), but sell for half of what a Kew goes for .