You just have to decide on whether you want to buy from a China based dealer or from an American dealer for a little more money.
If the light came with a defective battery....then what? Send the bad one back to China and wait for a replacement? It could take weeks.
Of course they might send one out immediately and not wait for the bad one to get to them first....who knows when you're dealing with overseas merchants. I don't like the ones that "protect" the bidders/buyers identities because you cant' read the buyers feedback.
I will say this....I have bought quite a few light related items from China on ebay and have not had any problems whatsoever. Yet.
As far as the light goes, it is probably as good as any other of its type available.