Anvil: Pricing for renaming weapons (e.g. a sword) is too expensive

What I expected to happen was...:
I expected that renaming an item (like a sword) doesn't cost much, because you don't have any advantage of it.

What actually happened was...:
Instead, it costs 39 levels. (Too much for renaming an item.. what if I rename the item first and then enchant it? I think renaming items should always cost about the same.)

So I assume that this is not intended (otherwise would be pretty disappointing and makes the anvil pretty much useless if can't use it with the very good items) and may be some side-effect of the current implementation.

Steps to Reproduce:
Make an awesome enchanted sword and try to rename it with the anvil.