The market offers up bargain opportunities every day. We don't always know what the opportunity will be, but finding one will supercharge your portfolio.

Master investor Peter Lynch said that one advantage of running Fidelity Magellan was its charter. It was a capital appreciation fund, giving Lynch the flexibility to buy in any investment situation.

And he took advantage of it! Big or small, constant or cyclical growth, asset plays or turnarounds. You name it, Lynch bought it.

While we should follow his example and look for the best opportunities in any form -- growth stories, turnarounds, misunderstood stocks -- there's one type that can be particularly rewarding.

Limited-time-only sales
The best companies grow steadily year after year, right? Wrong. Great companies have plenty of miscues along the way. But the truly great companiesrecover.

If step one on the road to great returns is to invest in great companies, we have to know what it takes to be great. Read Built to Last or Good to Great by Jim Collins. Read Common Stocks, Uncommon Profits by super-investor Philip Fisher. Another master, Warren Buffett, offers his thoughts in his annual chairman's letters. Read those, too. Trust me; you'll learn what makes a company great.

We'd all be rich if the only thing investors had to do was identify great companies. The second key, as Buffett advocates, is to buy them when they're on sale. And when do they go on sale? When there are problems.

At Inside Value, we know it's difficult to purchase companies surrounded by negativity. But if we can, the market offers the opportunity for big rewards -- if the problems are only temporary.

Here are some recent examples of great companies selling at discount prices for a limited time.

Low Date

Low Price

Recent Price*

Return From Low

Johnson & Johnson (NYSE:JNJ)

July 19, 2002

$41.63

$62.68

51%

Capital One (NYSE:COF)

Aug. 2, 2002

$24.70

$78.70

219%

El Paso (NYSE:EP)

Feb. 13, 2003

$3.45

$15.96

363%

*Price as of Aug. 1, 2006. All data from Capital IQ, a division of Standard & Poor's.

35% off
Johnson & Johnson's products have probably touched our lives at some point. Not just a Band-Aid maker, the company develops drugs and products that play a huge role in helping people get -- and stay -- well.

But July 2002 was not a good month for Johnson & Johnson. The Food and Drug Administration and the Department of Justice launched a criminal investigation into the quality of its anti-anemia drug Eprex after the drug was linked to serious illnesses in Europe and Canada.

That typically doesn't help your share price. However, if you were able to diagnose this as a great company that could recover from the trauma, you could have earned a 51% return. And with the investigation by the Department of Justice into the sales and manufacturing practices of its orthopedic device division DePuy (Stryker (NYSE:SYK) and Zimmer were also subpoenaed in June 2006), one has to wonder whether current share prices are a bargain today.

60% off
Financial services company Capital One also suffered a blow in July 2002. Regulators required the company to boost its reserves for bad loans by $247 million, and to make changes to its infrastructure as it pursued growth in the subprime lending market.

Increases for reserves means less profit, and implies that the company may have been too aggressive with its accounting policies. Investors didn't much care for the news, and the class action lawsuit filed shortly afterward certainly didn't help. As such, the stock fell 39% in one day, and a total of 60% to its low of $24.70.

95% off
The Enron collapse took down many energy giants, including Calpine, Dynegy (NYSE:DYN), AES, Reliant (NYSE:RRI), and El Paso. All of them watched their stock prices drop 90% from all-time highs.

Calpine's problem was in overpaying for its generation assets, then not being able to produce meaningful revenues from them. Yeah, value destruction.

Don't get me wrong: El Paso had plenty of troubles of its own, including overstating its natural gas reserves, manipulating natural gas markets, restating its financial statements, declining credit ratings, a large debt burden, and class action lawsuits. However, despite the issues, El Paso's assets continued to generate cash flow. Value creation.

Today, Calpine is trying to emerge from bankruptcy. El Paso? It's still getting back on track. But fire-sale buyers who bought El Paso near the bottom are up more than 360%!

Today's sales
Within the market, there are plenty of underappreciated, unloved, and misunderstood businesses. Add the right catalyst, and you've got opportunity.

Given the uncertainty surrounding its future growth prospects, First Data (NYSE:FDC) may be an interesting opportunity today. Berkshire Hathaway has owned shares for a while, presumably bought by investing guru Lou Simpson, and great value investor Jeremy Grantham is also an owner. In fact, Philip Durell, advisor-analyst of the Fool's value investing newsletter service, has laid out the investment case for First Data twice. So maybe it's one of those companies selling for 30% to 50% off.

On sale tomorrow ...
Who will be tomorrow's next big bargain? That's what Philip and the Inside Value team are dedicated to finding out. And their list of candidates is available with a free pass to Inside Value. Click here to learn more.

This article was originally published on June 24, 2005. It has been updated.

Fool editor David Meier owns shares of AES. Johnson & Johnson is a Motley Fool Income Investor recommendation. The Motley Fool has adisclosure policy.