I've bought a few filters from an e-bay sellers in both Hong Kong and mainland China. Transactions have been seamless.
I've also bought a few fountain pens (another passion) from sellers in China. Most of these transactions have gone smoothly, but I did have one instance in which the seller's description of the pen was inexact, and while the seller agreed to supply another pen (the shipping charge was MUCH greater than the selling price), the pen he supplied to address the problem still didn't match his description.
So my conclusion is that there is at least a potential for misunderstanding - a combination of language differences and cultural differences.