Do you have an actual example of a vendor, today, charging a higher license fee for IPv6 support?
Juniper. If you want to run OSPFv3 on their layer 3 switches, you need a quite expensive "advanced" licence. OSPFv2, on the other hand, is included in the base licence.
Our IPv6 topology is largely based on static routes because of this. There's no customers that are willing to pay extra for IPv6 support at the moment, hence we cannot justify the extra cost of the licences. It sucks. I hope Juniper will come to their senses soon.
It used to be considerably worse. As late as May 2009, Juniper charged $10.000 (list price) for an "IPv6 Support on JunOS" on license (for high end M/MX/T series), and the same amount for an E series IPv6 license. Fortunately Juniper seems to have come to their senses here, and these licenses are now $0. Steinar Haug, Nethelp consulting, sthaug@nethelp.no