Chances are, at some point while paying with paper money you've handed someone a $10 or $20 bill and later realized you got less change than expected. Perhaps the retailer mistook your bill for a smaller one. Or maybe you were just shortchanged. Either way, the gnawing feeling that you gave away too much money sticks with you.

Now, imagine handing someone a $10 or $20 bill that was actually worth $1,000, $5,000 or even $50,000. Sound implausible? Nope. In fact, it may happen more often than any of us think. A new book illustrates how we might be missing out on big riches.

The fourth edition of "United States Paper Money Errors" has just been released and is an eye-opening chronicle of "ordinary" paper money being worth many times its face value. In every case, the cause can be traced to human error. That makes sense. After all, our paper money is printed on machines built and operated by humans. Of course they are exceptionally skilled, but humans make mistakes. Fortunately, dealers and collectors pay big money for those mistakes.

For instance, perhaps the printing and images on a one-dollar bill in your wallet appears a tad blurry or fuzzy. Chances are it is a "multiple printing" variety. If the blur is subtle, that dollar can be worth around $1,000. If it's more pronounced it may be worth upwards of $2,000.

Equally subtle errors can be a bill that has an ink smudge or another that appears slightly faded. The first is one where extra ink was inadvertently applied to the bill during printing. Even a small amount of extra ink can boost the value of a one-dollar bill to $50 or more. And, if not enough ink was used resulting in a portion not being fully printed, values can range from $50 to $500. That includes something as insignificant as the serial number.

Even bills that aren't well centered are sought after. If white borders surrounding the rectangular image on a bill aren't even it can mean value. The more off-center the better. Known as "faulty alignment," bills that didn't quite get cut correctly are worth anywhere from $50 to $650.

Again remember that humans are running the presses and even checking printed sheets in the quality control area. Doesn't matter. As a species, we mess up all the time. Just take a look at the current presidential election. It appears to be one mistake after another. Of course, there's rarely a profit to be had for us in that arena.

To truly hit the jackpot, check bills to see if the denomination on the front matches what is on the back. For instance, what if a five-dollar bill has a 10-dollar back? Or, a 10-dollar bill has a one-dollar reverse? In those cases, the bills can be worth between $35,000 and $55,000 respectively.

There are many more types of errors — some obvious, others very subtle. Even two bills that may be discovered to have the same serial number can be worth over $15,000 for the pair. The common denominator of error currency is that all are worth many times their individual face values.

I'm not sure how much leisure time bank tellers have but after flipping through "United States Paper Money Errors," if I were one I'd be checking to see what was in my drawer. Knowing what to look for and keeping a sharp eye out can pay off. The same is true for clerks, retailers or anyone who takes the time to look a little closer to see how we humans may have messed up.

The 296-page book with over 550 photos identifying the errors has a list price of $27.95 and is available at many coin and currency dealers or directly from the publisher, The Coin & Currency Institute. An e-book edition for viewing on tablet devices is also available for download or on a USB flash drive for $17.50. For more information on either phone toll-free: 1-800-421-1866.

There's no mistake that the U.S. Mint has hit a home run with a new high-relief 1-ounce gold coin. Struck from pure gold, it has overtones of a historic gold piece that has long been a favorite of the American public. I'll give you all the details on that in the next column.

Editor's Note: A JPEG visual of the cover of the book, "United States Paper Money Errors" has been sent with this column.

To find out more about Peter Rexford and features by other Creators Syndicate writers and cartoonists, visit the Creators Syndicate Web page at