I never bought any of those from Hong Kong, and I haven't heard anything about the quality of them.
However, I won some items from sellers here in the U.S. Both transactions worked out fine. First one was for a front fairing and the other one was for a rear cowl.
I use PayPal for payment, although I sent a money order one time, because that was what the seller wanted.
I check the seller's feedback, to make sure they have 99.7% positive feedback or higher. That's not a typo. 99.7% or higher.
I check the seller's feedback, to make sure they have sold items of equal or higher value in the past.
I check the seller's feedback, to see if they have been around a while and sold lots of stuff, and gotten lots of positive remarks from buyers.
I check the seller's feedback, to see if his "customers" look like legitimate customers, not just shills.
Call me overly cautious, but when it comes to expensive items, well, I'm cautious.