I was just thinking today. I would love to invest in more Gold and Platinum but the only coin I might be able to afford would be the Gold Eagle 1/10 oz which currently costs around $200. I'd have to save 2 months worth of my coin-collecting money in order to just buy 1 single coin. Where with Silver I'd be buying over 20 coins with the same amount of money. Of course, if they made even smaller coins they'd be ridiculously small. But then I was thinking about all the 40% coins I buy such as the 1965-1970 half dollars and the 40% eisenhowers. By plating them (or is that called clad? not sure) that makes larger coins but still has good investment value in them. If somebody made coins like this that were layered with 40% gold or platinum, that would be great because they'd be decent sized coins but still contain precious metals and be affordable to buy on a regular basis.
The problem with someone making plated coins or even silver/clad or gold/clad would be people trusting purity. 40% Silver Kennedy halves and Ikes were manufactured by the U.S. government and fully guaranteed of purity and weight of silver. Same thing with the 90%. If Joe's mint were to start making clad or plated coins/bars people would probably shun them. JMO. I myself prefer Early U.S. gold, which it usually carries a Numismatic premium, but it's also got the history.
If you want some gold save your money and buy the 1/10th ounce coins. Then when you have enough of them either trade them for a larger piece at a dealer or sell them and buy the larger piece. You could also buy 1 gram gold 'bars' if you wanted to own some gold but they aren't really bars more like large flakes lol.
Adric, based on what you wrote, you can't afford to buy gold, so don't even think about it right now.
Royal mint has plenty of gold plated issues' they are typically plated over silver coins. Like this recent issues for 2012 Olympics image courtesy of Royal mint. These are commemorative coins not bullions' since the whole idea of bullion you know what you are getting for and supposed to act as investment vehicle. The bullion coin itself is supposed to be worth only its spot value with small premium, so the coins are mass manufactured using simplified designs and 999 or 22k material gold/silver to keep production costs lows. But i know grading companies and speculators have changed that whole notion...
My "HUGE" gold bar! and yes gram and grain bars are availble but will take you forever to build up to an ounce PS. 15.5 grains in a gram