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

Energy Conversion Devices (NASDAQ:ENER)

****

63%

GigaMedia (NASDAQ:GIGM)

*****

60%

Popular (NASDAQ:BPOP)

****

57%

Progenics Pharmaceuticals (NASDAQ:PGNX)

****

51%

United States Natural Gas (NYSE:UNG)

****

50%

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
Europe is raining on the solar industry's sunny-day parade. France started handing out the umbrellas when it cut its feed-in tariff 24%, and Germany dashed hopes of a break in the clouds with its decision to move up its own subsidy cuts and make them much deeper than anticipated.

Even though some players, like Suntech Power (NYSE:STP), derive less than half of their revenues from Germany, it’s still a bit distressing considering that Germany is one of the biggest markets for solar power. And while France's cuts might bring its tariffs more in line with those of Germany, that was a nascent market really beginning to heat up.

All this is why some view the developments as positive, particularly Energy Conversion Devices. It announced plans to establish a 30MW solar laminate manufacturing facility in France, saying it believes the government did the right thing in easing off the subsidy gas pedal before the industry careened out of control. Well, yes, but that can also be viewed as just so much spin.

Most investors aren't deterred though, as 92% of CAPS members rating the solar shop believe it will outperform the market. I'm not one of them, however, as I've had an underperform rating on ECD for a few months now. Head over to the Energy Conversion Devices CAPS page and drop a bit of sunshine on how you think it will be impacted.

No prescription for relief
Is it realistic to think that Relistor will realize its potential without a major partner? The market thinks so, and ever since Wyeth announced it was walking away from the drug (which treats the side effects of pain relievers) made by Progenics Pharmaceuticals, its stock has been getting some good vibes. After bottoming out in November, shares have wafted 34% higher.

Following Wyeth's decision to merge with Pfizer (NYSE:PFE), it decided to pay Progenics $10 million to return the rights to the drug while also paying for development costs. It further agreed to continue marketing the drug outside the U.S. for another year, meaning it wasn't such a bad deal for Progenics after all. It still has plenty of opportunity to find new partners.

While sales have been anemic, investors like CAPS member Baski101 remain hopeful that Progenics' financial position is strong enough to get it through this rough period. Baski101 writes:

Its basically cash rich, has a few good products waiting to be launched once a partner is found for marketing, and its current stock price is an all time low, which can't get any worse than this.

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.

Pfizer is a Motley Fool Inside Value selection. Suntech Power Holdings is a Motley Fool Rule Breakers recommendation. The Fool has a synthetic long position on United States Natural Gas. Try any of our Foolish newsletter services today, free for 30 days.

Fool contributor Rich Duprey does not have a financial position in any of the stocks mentioned in this article. You can see his holdings here. The Motley Fool has a disclosure policy.