You can order from AliExpress.com or Banggood.com. The delivery may be a bit slow and there are some fraudulent sellers there which may send you duplicate products. So make it a point to order from reputed sellers. Check their ratings and reviews before you place an order. Also use a coupon to save some $$
The main concern with buying a Chinese phone is whether or not they're selling you a US or International version. The International version is probably lacking a number of North American LTE bands, which could cripple your network coverage or just run the radios hotter as they're forced to hit more distant towers. At the least, check with your network provider's band use to see that you've got coverage with that new phone.
I bought a ZTE Axon 10 Pro last fall, but ZTE has a business presence in the USA, and they're selling a North American model.
Also, I remembered something else. You can face problems if your device stops to work. I had once ordered MI band and it stopped working after a month or two. And there was nothing I could do about it. Paying for shipping back to China was too costly for it to be worth it.