Well all I can say BugGold is that: Been there done it, paid nothing. I will qualify that a bit tho: I have always kept my individual transactions under the 10K Financial Transaction Disclosure level of 10k(specifically the reason to buy in small denominations). Completely anonymous, no ID required, never been asked for any. However, if your holdings are held in taxable, investment style accounts then there is a CGT liability.
I beleive certain forms such as Heirloom and Collectable items are subject to tax also(this could include coins held in a investment/trust style account).
Bullion under the bed is a bit different tho IMHO. Having said that the whole thing is a bit of a grey area. The following link may be of some help.
