Note: that was for a dedicated 10-gigabit link from specific location A to specific location B, plus a peering at one large IX, without any access to the rest of the internet.
Nonetheless it does give a ballpark for the cost of bandwidth being a lot lower than people think. A 10G internet connection would be cheaper to provide in some parts of that equation and more expensive in others - should end up in the same ballpark.
It was more than 5 years ago and was not a direct commitment. Another company was being used for their data centers, and this was a lease/rental agreement of equipment; Think colocation model, but where you're like 50-80% of being the main client of the data centers.
Add 10-25% profit for that company to get closer to true "raw transit" pricing from the carriers directly.
And telegeography just sells information, but they had a blog post that's now three years out of date reporting that "In Q2 2021, the lowest 10 GigE prices on offer were at the brink of $0.09 per Mbps per month. The lowest for 100 GigE were $0.06 per Mbps per month."
You need to factor in that your utilization won't be 100%, but if you're comparing 6 cents for a Mbps and and 5 cents for a gigabyte, then the exact point where AWS is 100x more expensive is when your line is 36% utilized.
The number above was a thousand dollars per month per 10gbps, and AWS would charge more than a hundred thousand dollars at the listed $0.05/GB price.