K 18WG means that the gold content of the necklace is 18K, which means that it contains 75% gold. Theoretically, 18K gold is more expensive than 24K gold, because more gold is needed to make it. But the value of the necklace will also be affected by other factors, such as brand, design, inlaid gems and so on.

If the design of this necklace and the gems embedded in it are valuable, then its value may be higher than that of the more pure 24K gold necklace. In addition, if this necklace is a limited edition or has special significance, then its value may be higher.

Generally speaking, these factors need to be considered comprehensively to determine the value of K 18WG necklace. If in doubt, it is recommended to consult a professional jeweler.