transport gold out of HK

2. “Once I buy gold coins in Hong Kong, is there any restriction to taking them out of the country?”
No, there are no restrictions for transporting gold out of Hong Kong as precious metals are not a controlled or prohibited item listed by Hong Kong Customs (rough, uncut diamonds are).
We have transported gold out of Hong Kong numerous times in our carry-on luggage without so much as a glance from security.
3. “Are there restrictions on bringing in gold coins when I return home?”
It depends on where you are flying to and what you purchase. If you are flying to North America, neither the Canadian nor US government considers gold to be a monetary instrument.
Maple Leaf and Eagle coins are technically deemed legal tender in each country, so you would have to raise your hand if the aggregate face value of the coins plus whatever other cash you have on hand exceeds $10,000.
Bear in mind, customs officials in North America have unlimited authority to do whatever they want, even if you are well within the law. As such, it may be advisable to have a receipt for the coin purchase in Hong Kong, as well as evidence for your source of funds (bank statement is sufficient).
If you’re ever in doubt about the regulation, ASK.
4. “Are there any countries that I should avoid for transporting bullion?”
Yes, absolutely. To name a few: Mexico. Thailand. Most of Africa. Russia. Uruguay.
I would also generally avoid Panama as well– the country’s customs regulations value gold based on its market value, not face value… and anyone who brings more than a trivial amount of gold into the country could end up paying an unnecessary import duty.

http://www.zerohedge.com/article/follow-physical-gold-arbitrage-trade