I found three pieces of rubble priced at 5k each in Luna on Baja - 2 small sandstone rubble and a cute plant (not even a fern graphic or garbage!) That was pretty surprising, and I nabbed up the pieces post haste.
I think the highest tier items such as fire will go for a lot (20 mill+), the next tier would be items like display cases and those tall bishops benches (5-10 mill), things like that, then the next tier would be wooden benches and tables that don't have a reproduceable graphic on the carp menu (1-2 mill for a whole bench or table), whole logs would be about on par with coconut trees and fig trees, unusual plant graphics would be a lower tier, maybe 100-200k for unusual plant graphics that are fairly common from this event.
Not sure how to place jewelry, I figure earrings would go for more than necklaces or rings since those don't take up a needed item slot, fancy dress would fetch more than pants, but these things are of no interest to me personally so I can't imagine shelling out any $$ for them. An avid jewelry collector would pay millions tho, certainly.
Wall pieces being so common I can see settling around 200-500k, and will increase in value (of course) as time goes on. I would personally pay more for the small sandstone stair pieces including the blocks.
Items that have a duplicate graphic that is craftable or growable will not go for much at all. Maybe in 2 years that stuff will fetch ok prices, but will never be really valuable.
These are just my guesses, I'm sure I'm not listing some of the neat exceptions to the rule, like the very cute lilypads which while are an 'unusual plant graphic' would fetch more than the regular unusual jungle plant type stuff.