Last week, the weighty 50p coin first issued back in 1969 began the process of being phased out in favour of an eight-gramme replacement.
A new bi-coloured pounds 2 coin will take the strain off its pounds 1 equivalent on 3 November, although recent reports that a pounds 5 coin would come into circulation next month are apparently based on a misunderstanding.
The new pounds 5 coin will commemorate the Queen's Golden Wedding anniversary and collectors can get it from banks and post offices at face value, but it is not intended for general use.
The new coins already feature in the Royal Mint's annual proof sets of currency coins which are offered each year to the 220,000 members of the Mint Collectors' Club, based in South Wales. Prices vary with the contents but this year's bumper set costs pounds 32.50 including VAT, or pounds 39.50 in de- luxe packaging.
Modern coins are not intended to be investments, but over time they become scarce. Pre-1947 silver coins are worth five times their face value for their metal content alone and uncirculated coins are worth much more to collectors. Even cupro-nickel florins from scarce dates like 1954, 1957 and 1959 retail for pounds 20 to pounds 30 in uncirculated condition.
There is also a secondary market in modern coin sets. Spinks, the antique coin specialists, now has a modern coin department run by Geoff Kitchin, and there are any number of coin dealers, many of them members of the British Numismatic Trade Association, and a special publication, Coin News, to keep collectors informed.
The first issue of coins bearing the head of Queen Elizabeth II and wrapped in a protective plastic sheet but excluding a crown coin sold for 62.5p in 1953 and are now worth pounds 15. Sets including the crown coin then cost about pounds 1 and now retail at pounds 55.
Recent sets can also go to a premium especially in years where the Mint has not issued a complete set of new coins for general circulation, and the uncirculated sets are therefore the only sources of coins to make up complete collections. No 50p coins dated 1974 or 1975 were issued for general circulation, for example, and coins from proof sets are worth pounds 2 uncirculated and pounds 3 to pounds 4 in proof state.
The special issue of 50p coins minted in 1992 to commemorate the EU council of ministers meeting in Edinburgh is also now in demand and will retail at pounds 5.
In some years the Mint has sold up to 170,000 sets of uncirculated coins, but only 57,000 of the 1993 set containing coins from 1p to pounds 1 were sold at pounds 6 a set. But those sets are the only source of 5p, 10p or 50p coins for that year and they now sell for pounds 12.
Back in 1994 the Mint sold a set of coins in base metal, silver and gold commemorating the 300th anniversary of the Bank of England. The gold set sold for pounds 265 but soon after they began appearing a collector noticed the pounds 2 coin did not have the value beneath the Queen's head. The Mint tried to recall them but not everyone responded and the errors are now worth pounds 400.
But not all investments pay off. At the top of the gold market in 1980 the Mint sold 10,000 sets of proof gold coins containing a half sovereign, sovereign, pounds 2 and pounds 5 coins to collectors for about pounds 1,200 including VAT. At one point they changed hands at pounds 2,000 but the gold price has more than halved since then.
Nowadays you can buy a set for about pounds 700 and a dealer will take a set off your hands for about pounds 450, which is not much more than the bullion price.
Subsequent issues have been better investments because sales have fallen to about 1,000 sets a year and have held their value, although if you want to sell you would only expect around 60-70 per cent of the retail price.
The difference is swallowed up by VAT, storage and administrative costs and the dealer's profit
The main guide for UK coins from Roman and Celtic times to the present day is Seaby's standard catalogue of UK coins, now in its 33rd edition, which is published this year for the first time by Spinks. It is now available from Spinks's book department - 5 King St, London SW1 - at pounds 15.