If I dump a truck load of sand on my drive way, and if you search carefully, you will find that I have dug many small holes in the sandy beaches around the world. This is the LOC (law of conservation). I get, only when someone else loses. Mass and energy cannot be created or destroyed; they can only be transformed or transferred.
You can see now that there cannot be any win-win situation. In every win-win situation, a careful analysis will always reveal a third party who will be the loser. Wining means profiting; profiting means cheating and violating the LOC.
If I have something, that I do not need it, and someone else needs it, then why not just give it away. Similarly, if a store has something that I need, I just go and get it. There is no need to exchange or barter with something else. After all the money that we are using is free for the CB (central bank).
All the products we are using are made of resources from nature. Nature is free for everybody. Nature cannot and should not be allowed to confiscate. Thus all products are, in reality, free. Anyone who needs them should be able to get them free. So the concept of MLE already exists in principle.
There is no need to create and maintain an artificial win-win situation.