Absolutely. Amazon is selling magic beans[0], quite often. They have lots of tools that they convince new engineers are the best. But quite often, if not always, the existing FOSS tools (upon which most of AWS is built and from whence they came) offer superior performance at a far better price point for most scale.

In tribute to the Dead Milkmen, in case you want to sue me, I'm talking about this book - http://www.amazon.com/Magic-Beans-Nutrient-Rich-Disease-Figh...