[remosi]

There are complications, some IP's might be free, some might be cheap (caches, local peering), some might be expensive (transit). The price might vary on time of day (a lot of eyeball networks are near idle when everyone's asleep). The price might vary on the DiffServ bits. Then there's the question of what is it billed in (what if one connection is billed in GBP and one is billed in USD?). Maybe one connection has the first 1G free. Should you advertise the entire connection as being free until you hit that 1G, then advertise it as the overage? Or should you do something to try and make sure that the 1G lasts the entire billing period? If it's a peering connection, maybe it's free so long as the in:out byte ratios are within 10%, so how do you represent the price of that?

But for the simple version, I think RSVP is supposed to kinda support this, but it would probably be difficult to shoehorn in, even ignoring all the stuff I mentioned above.