I had a unique lead pattern 1982 20p which was sent to the designer with RM letter dated Nov 1981. Based on that and the price it sold for, I don't think there is a chance of unique decimals raising much more than £1000 - £2000. The main reason is because the demand isn't there and nor are the collectors with the money, compared to the older material. The coins don't have any kind of almost mythical status like 1933 pennies and American rarities etc either, and possibly never will. Maybe in a couple of generations that will be different, and there are always people that seem to be able to afford and gladly pay well over the odds! With the gold 50 pees though, err, they are unique, but there are 29 of the bloody things! 29 unique 50 pees, each with a design as quickly bodged together as the next. The RM do produce very limited numbers of platinum crowns with mintage of sometimes just 150 pieces. They seem to 'sell' (assuming anyone actually buys them) for about £6400 each! Who on earth buys them? Seriously, where are the people that buy them? Anyone here ever bought one? Anyone know anyone that knows someone that has bought one? Perhaps they go to museums or into collections of super-rich people. Which is odd, because normally super-rich people are quite clever and would probably invest in platinum by buying it much closer to the bullion value. It would interest me how many of the 150 they actually sell, as the mintages the RM quote are usually maximum mintages. The expensive ones like that are made on demand. From experience, I find that the people that collect modern coins don't actually have any idea about coins and they don't usually have much money either. They have a subscription with the RM, they get them in the post and put them in drawer after looking at them once. Then they die and the coins get inherited by someone who contacts me, and I tell them that they are just worth the bullion value (which is often more than the pre 2000s coins cost because, luckily gold/silver has gone up quite a bit in that time), despite the fact that the original clueless purchaser paid 3x the then bullion value for them!