I have high value coins in my collection.....without giving away how many I will say more than one. They have all been bought online, mostly on
ebay. I follow several rules for high value coins.
I will ALWAYS buy from reputable sellers, the same ones that have both online and brick and mortar stores. Also, all my high value coins have been professionally graded. I realize those can be and are counterfeited, but at least a graded coin has the possibility of being cross referenced online from previous sales and serial number checks. My third and most important rule......if it is too good of a price to be true then odds are it is fake. Unless the seller is in dire need of quick cash, it will not be offered considerably lower than fair market value. 99% of the time a collector owning a high value coins is an educated and hopefully experienced collector and is willing to wait to get fair value for his/her coins.
I've been stung before, and these rules have kept the chances of it happening again to a minimum.
As for the registered package going missing......what do the search results tell you when you track it?