Whether you should buy from Chinese sellers that are out of the cosmos of Taobao and Weidian depends on their trust level in the community. If this can't be judged, you should make your own assumption based on where and how you pay. Without more context, Yupoo sellers need to be checked before they can be trusted.
If it's a seller that ships domestically and you end up ordering through a trusted shopping agent, the risk to get scammed is extremely row, that's what agents are there for. If they ask you to pay the privately, through a non-refundable method (Paypal family and friends, crypto, Western Union) that should be seen as a warning sign.
Unless the sellers is really well known and has tons of provably independent reviews, I definitely recommend you stay away and look for a trusted seller and preferably purchase through an agent.
added: 6/26/2023