I like the idea of a recycling machine. It would be difficult to balance though. Maybe if it could keep track of the average sell price of each item and give you 10% of the value. Make that scale with power up to a total of 50%.
Got some dirt you don’t want? Throw it in the recycling machine for 90 -450 coin per smart stack. Maybe have a spark cost for higher coin output or higher tier items.
It would give people a means of generating coin without having to set up our own shops.