Rising prices mean less desire, or ability, to think past short-term needs to long-term planning. The high cost of everything, over a prolonged time, could also blow your investing assumptions out of the water if you base your plan on an otherwise reasonable assumption of 3% to 3.5% a year in cost of living. Underestimating this cost -- easy to do without a crystal ball -- will eat away at your returns. Adding insult to injury: The government's inflation calculations don't even include food and fuel. So even if all those economists are claiming a low inflation environment, your pocketbook may disagree. Added to the mix are family expenses. The Merrill Lynch survey found that 56% of mass affluent parents have paid or expect to pay more to send their first child to college than they had expected when the child was born.