In The Fellowship Of The Ring, when Gandalf reveals that Thorin gave Bilbo a shirt of mithril, Gimli says it was a kingly gift.
He is not exaggerating. He is understating. Mithril isn't just something incredibly valuable that only a king would have, it's a strategic asset for an entire kingdom. It used to be Khazad-Dum's most important export. Now that the source of mithril is blocked, finding an entire mail shirt of mithril would be like a post-apocalyptic society coming across a working solar-powered water desalinator. Not just a pretty thing for a king's delight but a literal national treasure that a king would employ for the security of his people. That kind of kingly.
So what I imagine was going through Gimli's head was long the lines of "What the fuck. An entire shirt of mithril. What the fuck did Bilbo do to earn that. I mean yeah sure he saved the lives of Thorin's company multiple times and then burgled a dragon and gave out the secret that led to the dragon's death so that the Kingdoms of Erebor and Dale could be restored but still, what the fuck."