What do I consider British Coins can yield as an investment? Firstly they are easily saleable and they are portable, but not in the same way as stock market or bonds. So we now turn to compound interest. Coin collecting, like many enjoyable pastimes in life, is actually going to cost you money. So why do people think that buying rare coins is a form of investing? As a collector we do not cost each and every coin in the collection, some rise, some do not. We look at a collection of pleasure and this way we can be pleasantly surprised if over a 20 year period we actually benefit from 10-12% compound appreciation. Yes, some coins we will lose money on, others stay stagnant and others rise to seemingly amazing prices. We should take into account, fashion, eye appeal, quality and rarity.