What if make some kind of money... For example, make from 1 mese 99 money (or other rare material, which is hard to find (nyan cube?) and useful in many crafting recipes). To save useful of money, make inverted recipe which is converting 99 moneys to 1 mese...
And make some kind of automatic showcase, as a block... where we could set up a price for every block and sell them to others...
Why this idea? because some blocks is very hard to find, but always have other blocks which don't need to me but could need to others.