Question Is this fake or real? RX 570 for $100

Agreed. It ships from and is sold by Amazon so there's not an individual selling a fake. You are covered by their A-z guarantee. It's only $128 over at another site and the 570 performs similarly to the GTX 970 which can be found for $100 for the smart shopper.

I purchased a pair of Rocky work boots for $48 that normally run $169. Amazon does have some pretty good pricing.