There are three kinds of jadeite, ABC. Except for A, they are all hand-processed and worthless.
Just ask them for a certificate. There are several quality inspection stations on that street. Just insist on the certificate.
As long as there are products on the certificate, you are not afraid to buy fakes.
But the price is hard to say. Depends on how you want to pay it back. I can't teach you now
Just watch more and do more. There is a big difference between hundreds and thousands.