If you look through the complaints and negative feedback of that ebay seller one gets the impression that most are rooted in the customers not reading the description thoroughly.
Lowpriceshoppee offers used and even shop-demo phones for very cheap and most negative feedback is from people expecting the devices to be new...
Also many complain about weak spare batterys, allegedly sold as originals.
In defense of the complainers, maybe those discriptions where indeed faulty, but buying an aquafish should be save.

If you only consider shipping complains, the seller would at least have ~95% from my estimate.