You didn't include the price of the one you found on Amazon, if it's this one, it's $69.97, the same price as the one sold by Raspberry:

https://www.amazon.com/Silicon-Power-200MB-Compatible-SU01KG...

I'd buy the one from Raspberry just because I know they've tested it and it works well. (plus I prefer to not buy from Amazon, but that's just my personal preference)