I have a friend I'm trying to shop for, and he plays wow a lot. Any ideas for a good present?

I'm totally clueless about wow, except that you play it online and it's an MMORPG. Considering my only real experience with MMORPGs is Runescape, and that was quite a bit ago... I don't think they're quite the same.

What can I get a wow player for Christmas? I'm pretty open to ideas, but sadly, I don't have enough money to buy him a new computer or anything super expensive, but I'd like to at least make sure he'll like the gift and it'll play to his main interest.

Thanks r/wow, in advance!