What is CCCP 30 gram 999 worth?

"CCCP" are the Russian initials for the former USSR, 30 gm would be a weight, and 999 is a fineness (the purity in parts per thousand) so it's a reasonable guess you have precious-metal bullion piece from the old Soviet Union.

30 gm is slightly less than 1 troy ounce, the (unusual) unit for measuring precious metals, so your piece is worth roughly the price of one oz. of gold, silver, platinum, etc. just for its metal. The fact that it's from a country that no longer exists may add something to the value, though, so you should check with a jeweler or coin dealer.