I'd guess that the median economic value of the contents of some random container that's been saturated in sea water is probably pretty low. The container itself is worth a bit if it's still usable as a container, otherwise it's what it's worth as scrap metal.

I'm having trouble imagining many things that would still be valuable. Even things in sealed containers might be crushed by the water pressure. Other than gold bars, what would still be useful? Construction-grade lumber, maybe?

I could imagine this being a rich person's hobby. And maybe the basis of a Netflix series or something, like shows about the gold miners in Alaska.