If Alice works 8 hours and exchange her products with Bob's products, which also cost 8 hours to produce, there is no scam involved, just fair trade. Similarly, if the cost to produce certain amount of money is similar to the value of the product those money can purchase, then it is also fair trade. This means, if the amount of goods that need money to trade increases, the cost of producing money should also increase. Bitcoin is a perfect example of the fair trade principle