As to your example, it does not hold water because no one is talking about all the other goods and services you mention. If everything goes down in cost, we can assume deflation has occurred and money has become more valuable. If so that plane ticket just went up in relative cost in balance with the money you "saved" elsewhere, so you are at break even. Otherwise stated, you just might as well contrive your long lost uncle also leaving you a million dollars along with your other hypotheticals; it would be just as relevant. ;-)