All the stuff I've had off eBay (not much) so far has been good, or leastways, as good as I expected. Only problem I had was a 99p thermocouple plug which failed to arrive, I contacted the seller who sent another one out, still didn't arrive. Don't know what happened there, something to do with the mail I expect.
I have been buying off shore components for the last three years almost exclusively. I have only received one bad part in the entire time I have been doing this, I just received the defective part on Tuesday and it was a 16 key keypad and the numbers were in the wrong order. Other than that one sub par part I have never had any issues at all. I do however check every part I install prior ro installing it to make sure it conforms to the specs of the component. Never had a problem and for the money you cannot go wrong. Some will belabor the whole bootleg parts concern, but there are legit parts houses just trying to earn a living a 1/2 penny at a time. So I don't hesitate to buy off shore if the price and delivery schedule suits your needs. Good luck and have fun.