Upgrade from 4 to 6?

I have a new MacBook Pro... I have the original full copy of Parallels 4... I then upgraded to 5... Now I want to update to 6... Do I have to do that all over again on this new computer? Start with 4, then do the two updates? Or would it be better to just purchase the full copy of 6?

 

You do not need to install old versions to install an upgrade version of Parallels Desktop. When you buy an upgrade, you are upgrading the license, not the individual files. Every install, upgrade or full, is really a full install and does not depend on old installs. You will need the old version's product key to activate the upgrade if the older version isn't installed.
http://kb.parallels.com/8831