I’m going to stick with DIA for this post, too.
Specifically, I want to know if Tier 1 IP providers charge more for DIA service than others. This is a myth I’ve actually argued in favor of in the past. It is certainly true that some carriers can provide a higher level of service, i.e. traffic that takes the fewest hops between destinations, and maybe even traffic that never touches another provider’s network. This might warrant higher prices.