The license you're talking about is THE LICENSE. There is no NEW License. There is no OLD License. There is just the License There will be no bill for $1,2000 since it's impossible to buy anything except a license of 2011. Autodesk does not sell licenses of old versions no matter what you did.
You don't activate a license. You buy a license and then authorize it. You may authorize it multiple times but it's still one license. The only way I know to void a license is to buy a newer release. Then, barring Subscription, your old license is invalid. It doesn't deactivate. If you wanted to break the license agreement you could still run the old license until something stopped it from working. Then you couldn't reauthorize it. I know people who still have valid licenses of R12, now about 20 years old.
If your boss is still giving you a hard time about it you need to get him to talk to your reseller about this. Your reseller can assure him there will be no charge for the reauthorization and that it is business as usual.
HTH
Allen
Allen Jessup
Engineering Specialist / CAD Manager