Don't believe it, some people think it can last for three years, and there are two kinds of results. First, the business disappears before it expires, the money can't be refunded, and the things are yours. Second, it was found that the jewelry depreciated due to improper storage and use, and refused to refund. Few people succeed in getting the full amount. The merchants who really do this are all aimed at some fine products, diamonds above 1 carat, jadeite with excellent appearance and so on. The normal increase of this kind of thing is 15% per year. After three years, no one is willing to refund the payment, which is not cost-effective.