In downtown Oklahoma City, where the parking meter was invented, a quarter will rent a space at the curb for 15 minutes. Drop a quarter in one of Oklahoma's ever-increasing numbers of slot machines and you may boost your buying power dramatically. As long as you're gambling, you might buy one share of one Oklahoma's beaten-down stocks, such as AMS Health Sciences. The Oklahoma City company is in bankruptcy, but still a going concern, and trading for 4 cents a share (additional commissions and fees almost certainly will apply). If you can find a penny somewhere, it and a quarter will get you a postcard. Some vending machines will provide a piece of gum, candy or trinket for a quarter, although the numbers of such machines are small and shrinking. "A piece of candy,” the owner of Oklahoma Vending Co. said. "That would be literally the only thing I can think of.” The local cafeteria will part with a cup of ice in exchange for a quarter. You might be able to find some kids selling lemonade for two bits, but it's not likely (certainly not during the last week of January). But we shouldn't be surprised. Inflation has eroded the buying power of our pocket change. The quarter we slap down today is worth just 3 cents in 1950's buying power. Looking at it from the opposite perspective, 25 cents in 1950 had the buying power of $2.15 today. Economics professor Sue Lynn Sasser of the University of Central Oklahoma said inflation erodes our ability to buy things. But in small doses, inflation is preferable to its opposite. "What you really don't want to get is deflation,” Sasser said. "Imagine if everything you purchased, your house, your stocks and investments, was worth less than what you paid for it.” Deflation is what threw the Japanese economy into chaos during the 1990s, Sasser said. A healthy economy typically generates a small, controlled inflation rate, she said. And that's why a quarter feels like 3 cents to some of us. Say, buddy, can you spare a dollar?