You're changing value stores in this scenario, which mitigates the loss but doesn't eliminate it. WHat makes you think that $10 accurately represents some set of physical goods for which it can be exchanged? What about when you start exchanging like-for-like at different agreed rates? If we equate wealth to money, and money is largely based on shared faith and acceptance, then when that agreement shifts wealth most certainly is created and disappears out of and into thin air.