Here is a breakdown of what I feel your Rubble is worth...
1. Plants, stones and wall pieces are very common -- the gray and black ones are worth more
2. The tree stumps come in three pieces -- too bad you only have one of the three
3. Plants go for 350 to 600 (black and grey slightly more) -- Trees a little more around 500-800
4. Sea Shells 500k each
5. Trees and Ferns are the best sellers
You do not have any of the really sought after pieces such as Reagents, furniture, food, specific items such as Rubble Display Cases, Boat Pieces, floor tiles...etc.
You might try placing 4 to 5 items in a bag and selling in one of the auctions on your Shard. Starting bid at 2m and see if it sells. Or, advertise on Stratics forums under Rares -- Collection of 52 pieces of rubble, 15 million, which is my estimate of what the collection would sell as a whole.
to give a poster a reputation bump!