G750 is 750 thousandths of gold, which is what we often call 18K gold; If it is a ring without an interface, then 18 is the size of the ring, which is often called 18.

The price of 18K gold ring is affected by the price of gold, because its main component is gold, but after weighing, it will be found that it is more expensive than the gold ring, because the complexity of the process determines its final price, so I can't give you an estimate here.