There have been a number of times where I have bought too many of a certain block, or found my chests are full of random decorations and building blocks that I don't need. Which is why I've thought it would be a good idea to add a sell option to the DMU shop.

Each block sold can give the player the same amount as it cost to buy in the first place, or a little less to deter people from buying the wrong amount.

Scenario:

I have made a secondary interior for my TARDIS with a Christmas theme for the holiday season But for the rest of the year, it sits there not really contributing to the function of my TARDIS. I recently decided to dismantle that interior and stick with my primary console room, which I can simply decorate when the season arrives. Back to the point, I now have chests full of TARDIS controls, fireplaces, Christmas wreaths and trees, and general junk that I dont really need. It would be helpful to be able to sell the blocks I don't need anymore. It would save space, help me make some money (to save for the $40,000 elitra), and make some builds look cleaner by giving players the option to sell entire console rooms.

I'm not sure how the money system works on the DMU, but I assume it wouldn't be too difficult to implement a sell option to the DMU