retire on (some amount of money)
To have a certain amount of money in one's savings or pension on which one will survive during retirement. I've been putting together a sizable nest egg to retire on once I turn 65. More and more people are finding out that you can't realistically retire on the state-funded pension alone.
retire on something
to quit working and live on something or a particular amount of money. I already have enough money to retire on. I cannot retire on a sum like that!