Are you talking update or upgrade?
This is what Nero site says.
Updates are for free, but not Upgrades!
If we are talking about Updates, we mean updates within a version: e.g. from Nero 188.8.131.52 to Nero 184.108.40.206. Updates only renew already existing programs. The previous range of functions is preserved but brought up to date.
However, Upgrades are e.g. from Nero 5.5 to Nero 6. You can find more information on Upgrades"