Bruce Wayne and Lex Luthor are known as two of the wealthiest men in the world in the mythology of DC Comics, but considering that Aquaman is the King of Atlantis, would his wealth dwarf even theirs?

Seems likely. All the gold and jewels that ever sank beneath the sea belong to Aquaman. That's thousands of years of lost treasures just sitting around. Not to mention the historical significance of every individual coin adding on to the value.

Very likely.

Think about what some millionaire collectors would give to get their hands on something that disappeared a thousand hears who that Aquaman could very likely have stashed in an undersea cave somewhere. The rarer the find, the more the value if you can find the proper buyer.

There have been a few appearences of Aquaman's wealth throughout the characters history. One of the funniest is when a sea monster wrecks a city and Alan Scott and Jay Garrick ask him to repay the damages and he casually summons two dolphins to carry a chest of gold to repay it./

However, they will never use Aquaman's wealth as any sort of interesting story point - especially when he's on the JLA. As far as money goes, they'll always resort to Bruce or Lex first.

He gave the waitress who's working three shifts to put her kids through college gold doubloons! Presumably worth enough to put those kids into college cause ...

Technically yes.

Garth once funded the Titans as well when they were rebuilding.

Also I'm fine with one of Aquaman's assets being unknown to the general public. It makes their reactions even better when they realize he is wealthy.