Making this call didn't require me to be a Nostradamus. It's basic free-market economics. Internet IPv4 addresses are now in short supply and with no more ever coming down the pike and the demand for Internet addresses increasing it was only a matter of time and dollars. Of course, everyone should be switching over to IPv6, but given a choice between buying their way--for a while anyway--out of a problem or investing in a major network infrastructure, Microsoft, at least, is going for the buy option. It won't be the only one.
Be that as it may, Microsoft is paying $11.25 per IPv4 address. The deal was put together for Nortel by Addrex. This rather mysterious company is one of the first, but most certainly not the last, IPv4 address brokers.
So what kind of market do we have now? Black? Gray? Polka dot!? Good question. Buyers, sellers and the RIRs are still working out what will be good answers.
IP addresses are virtual property, but ARIN has its own set of rules on how they can be transferred. A buyer has to show that they need the addresses and can only sell a year's supply at a time. As for the price, Curran said. "ARIN is not a party to that. That's between you and the recipient." Of course ARIN isn't the only Internet RIR and they may set other stricter or looser rules and conditions.
ARIN or no ARIN I think we're in for a brief--no more than two years-of wild and woolly IPv4 address trading. After that, we'll be well on our way to the IPv6-based Internet and we won't have to worry about running out of addresses until the Federation of Planets' interstellar Internet has been set up.