Having recently received the latest fake copy of Sapphire, the $900 one on eBay still looks real to me. The fake has improved some of the colours, mainly the yellow/pink gradient in the text at the bottom and the purple of the main character, but the blues are still off and on the rear the white border is still present around the game screenshots.
If that $900 copy is indeed a fake, it's a 100% perfect reproduction of the original, at least from what we can see in the pics provided anyhow. As odd as it sounds, I think it's more likely to be real than a perfectly reproduced fake.
I might take some scans/photos of the most recent fake version, as things have changed a little and the info and comparison shots between the fake and real copies is now outdated.