When should I name my tools?

I found out that naming your tools in an anvil will initially make repairs to tools more expensive than not naming a tool but after a while, an unnamed tool will become completely unrepairable while you will be able to continuously repair a named tool forever. So, when is the best time to name the tool to save the most amount of xp? Before or after enchants (I plan to use books and enchant as much stuff on each tool as possible)?