You love buying your shirts when they go on sale. And who can resist a buy-one-get-one-free offer? So when our stocks go on sale, why do we bemoan their low prices?

Smart investors like Warren Buffett or Marty Whitman love it when their stocks are suddenly selling at bargain-basement prices. For them, these companies become no-brainer buys.

The investors in the Motley Fool CAPS community also like a bargain, apparently. Below, you'll find five companies whose shares are selling at least 50% below their 52-week highs, but which still earn high honors from our investor-intelligence database. Consider it a BOGO sale on stocks.

Stock

CAPS Rating
(out of 5)

% Off 52-Week High

Isis Pharmaceuticals (NASDAQ:ISIS)

****

52%

National Bank of Greece (NYSE:NBG)

****

53%

Neutral Tandem (NASDAQ:TNDM)

*****

56%

Spectrum Pharmaceuticals (NASDAQ:SPPI)

*****

56%

Western Refining (NYSE:WNR)

*****

73%

Naturally, we want you to look a bit closer at these stocks before buying. You can get low-priced appliances in the dent-and-ding section of your home-remodeling superstore, but their quality might not be so good. Same thing here: Make sure there's nothing seriously wrong with the company before you plug it into your portfolio.

Take two, they're small
Whew! That was close. The euro finally rebounded to a one-week high against the dollar as concern about Greece collapsing from its failed monetary policies began ebbing. Until today it seemed as though the country would suck all of Europe down with it, but the EU and the IMF said they were pledged to help the nation so long as it was willing to do what was necessary to help itself.

Not that any of that helped National Bank of Greece, the country's largest lender. It shares were down more than 3% yesterday, possibly because despite all the feel-good rallying about a deal, Greece's economy remains on the ropes. Public debt is expected to rise to more than 120% of GDP this year and could go as high as 125% of GDP next year. Rating agency Fitch's has downgraded the country's sovereign rating due to a lack of credibility -- let alone confidence -- in the ability of Greece to get its financial house in order.

Recently, people have tried to pin a lot of the blame for Greece's current predicament on Goldman Sachs (NYSE:GS) for a derivatives deal, however the deal was pretty much penny ante stuff -- a $10 billion cross-currency swap -- considering the hole the country finds itself in (debt totals $398 billion), and it seemed more like a convenient way to continue using the investment bank as a pinata.

While CAPS member yujin7 believes it may take divine intervention of an Olympian sort to save the bank from ultimate collapse, Superdrol sees the brief respite the stock enjoyed as much ado about nothing and figures it will continue to fall.

Although the Greek bank has taken many hits over the past year, 97% of CAPS members are counting on more than a clash of the Titans to bring it to its knees. So is it as lovely as Aphrodite or more akin to Medusa and poised to turn investors to stone if they look its way? Let us know on the National Bank of Greece CAPS page if you're girding yourself for battle like Athena.

Thanks for the compliment
Refiners saw their margins slide during the global economic recession that caused demand for oil products to wither, and we haven't been hearing too much anymore about "green shoots" sprouting up. But it's likely margins have reached their nadir and investors like CAPS member kahunacfa think its time Western Refining in particular will see them rebounding.

Refinery margins are on the rebound having been hammered during the Depression of 2007-2009. Crude prices are expected to be range bound from about $50 to $72 bbl for the next several years. Reduced price volatility is a favorable operating operating environment for efficient refiners like Western Refining.

Yet some oil companies aren't so sure. ConocoPhilips, for example, suggests that unless there's a substantial return of demand margins will stay low. BP (NYSE:BP) has similar reservations, particularly in light of its refining business reporting adjusted earnings of only $15 million -- well below the $635 million analysts had anticipated.

CAPS members would seem to have more confidence than that with 96% of the more than 1,100 members rating Western Refining believing it will outperform the broad market averages.

Have half a mind
It pays to start your own research on these stocks on Motley Fool CAPS. Read a company's financial reports, scrutinize key data and charts, and examine the comments your fellow investors have made, all from a stock's CAPS page.

Sign up today for the completely free service, and tell us whether these stocks are twice as good at half the price.