We humans are a curious sort. Nature suggests so many animals quickly learn from their mistakes, are intuitive enough to know better, or instinctively avoid them. Not us. Even with all our top-of-the-food-chain intelligence we make the same mistakes over and over. Of course, there are disreputable people out there who depend on us doing just that to make their living.

Because most have a sentimental (as well as greedy) streak, unscrupulous people often deal in "collectibles." They dupe others into paying way too much for things that aren't valuable and have little chance of becoming valuable. Their favorite target has become elderly consumers, who can be confused or easily coerced into a purchase.

I have no tolerance for that. And because it's becoming more common, I thought it wise to offer suggestions to avoid it. The website Scambusters offers tips that I've slightly modified to apply to those who read this column. Here are 10 ways to protect yourself or someone you know:

1. NEVER rush to buy a "rare" coin, stamp or piece of currency. It will not skyrocket in value overnight, this week or next month. Take time to evaluate what's being sold.

2. Do a little research on the reputation and reliability of the seller. How long has the company been in business? Any Better Business Bureau claims against it? It's easy to find out.

3. Confirm the seller will buy back your coins, stamps or currency should the authenticity or grading come into question. Be sure it's guaranteed.

4. Be sure they agree to your obtaining a second opinion about the grade and value as soon as you receive your coins.

5. Confirm the grades of the collectibles with an independent source. NOTE: Not all grading certificates are from reputable third-party grading services. Be sure they are certified by well-known and respected companies (e.g., consider sticking with Professional Coin Grading Service, ANACS or Numismatic Guaranty Corporation for coins).

6. Shop around. Consult several dealers before buying. Check prices in leading publications. And consider purchasing at large collector shows with multiple dealers. Then you're guaranteed to compare apples to apples.

7. TAKE POSSESSION OF WHATEVER YOU BUY! I can't scream this LOUD enough. Never allow any company to "hold" your items for you! Too many have disappeared that way!

8. Never give your credit card number to someone who calls you. That is a surefire way to get scammed.

9. High-pressure sales tactics are the human version of animals instinctively knowing about danger. Refer back to No. 1 in this list. Don't rush into anything!

10. Don't be duped by statistics of others making boatloads off of similar collectibles. If the items were slam-dunk moneymakers, the people selling them would buy all they could and not tell you.

There are at least a dozen more caveats I could offer, but the very best is the world's oldest adage, "caveat emptor," "let the buyer beware." A great way to do that is also one of the least expensive. For coins, it is referencing the "A Guide Book of United States Coins 2015," also known as the Red Book.

Now in its 68th edition, the 440-page Red Book is far and away the most recognized and referenced resource for coin values in multiple levels of conditions. The greatest value of the book is being a common sense guide to the value of most every U.S. legal tender and bullion coin. Sure, there are some extreme rarities that sell for millions of dollars — 65 coins to be exact — but the vast majority are reasonably priced based on their scarcity (or lack thereof) and condition. In short, if someone is selling a coin for higher than the Red Book lists, beware!

Printed by Whitman Publishing, the 2015 Red Book is available at virtually every coin dealer, major hobby shops and booksellers. At $14.95 in softcover and $16.96 in hardcover it's one of the smartest buys anyone considering buying coins or precious metals can invest in. For more information or to purchase online go to: www.Whitman.com.

Editor's Note: A JPEG visual of the cover of the 2015 Whitman Guide Book to United States Coins, the Red Book, 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 www.creators.com.