I can say... I have seen a replica of the pendant on ebay from someone in France... it was not 100% like the official version but it was close enough. They were charging roughly the same price.
Yes, go for the official version, I have one myself. Just be careful when cleaning the inside of it. 925 is a soft metal and is scratched easily, so the stone in the sphere may rub against the back and scratch it, and its damned near impossible to get those scratches out once they're in there.