I suppose you have the same coin shows, estate sales, antique fetes, as well as access to ebay France, ebay UK, and ebay Deutches, that we might have here...but with a whole lot more history. I've been focusing on high priced numis, such as the America the Beautiful 5 oz. When you buy them when they first come out they are sold for ~$110, six months later they automatically increase in value to the $150 range. In a year they are $190... Bullion would have to see spot double to realize similar gains.
S~P