Just for what its worth I had looked at peering and while it can vary it seemed a lot of places don't consider anything less than 100mbps (of traffic being exchanged) worthwhile... unless you want to pay them.
I'm LOL at the whole NF Cache idea.
Lets do the actual math. That 4RU box is 10Gigabit attached, intended to service 5Gigabit constant user stream (up to 8.5Gigabit, which of course is all you want to saturate a 10Gigabit line anyway - 85%)
So at 5Gigabit per second you are transferring 2.25 TerraBYTES per hour, 54 TerraBYTES per day! Or 1.6 PETABYTES per month!
So based on TBus' 20GB last month, he only has to grow 100,000 times bigger to be up to 1.9Petabytes and be in the NF cache ballpark