Earlier quoted context omitted.
... which is also wildly overpriced. According to multiple sources, Internet transit in the US now costs less than 1$ for a 1 Mbps line for large deals, which translates to 1$ for 324GB, which translates to 0.003$ / GB. Amazon charges 15-30 times that. (it appears that traffic can be much more expensive in places other than the US and presumably Europe)
It may cost that much to buy that capacity, but it costs a lot more than that to run the large scale organizations (CAPEX/OPEX) that build and buy these services. You're not just paying for a pipe, you're paying for the corporation.
You are paying their profit margin, yeah.
It is wildly overpriced, no matter how you look at it. Operating costs even when done on a much smaller and more inefficient scale than for AWS do not make the total cost for incremental bandwidth usage THAT much larger.