World Coin Mint Sets

As a general rule, coins are more valuable when bought and sold individually rather than sold in sets. Whether you keep them as a set or break them up is largely up to you, and whatever storage system you've got.

I collect coins, not packaging. If I find the packaging is an inconvenience to storing the collection how I wish, I get rid of it. If the packaging is "reusable" (eg. a plush padded box) then I keep it in a bag somewhere. If not, throw it away. I tend not to actually do so with officially issued sets, but any "unofficial sets" I buy get the chop straight away.