Earlier quoted context omitted.
Searching for terms like "wholesale bandwidth transit" might be a better reference for comparison of actual cost. The providers you mention are depending somewhat on customers that statistically underutilize what they have and using obscure TOS clauses to chase away heavy users.
That's the list price. You don't pay the list price if you purchase at high volume. Bare metal and VPS providers are surely very high volume customers. This is perhaps an argument against pure DIY colo, but most small scale colo isn't connected "naked" to the Internet but gets racked in a data center that offers a bandwidth package and does peering for you. The only people who peer directly tend to be clouds, bare me…
AFAICT we had a blanket 20% off the bill, nothing special about egress.