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 three 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 12-Month High

Delta Petroleum (Nasdaq: DPTR)

*****

68%

NCI Building Systems (NYSE: NCS)

****

61%

SmartHeat (Nasdaq: HEAT)

****

51%

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
The collapse of energy prices wasn't kind to Delta Petroleum, whose price slid from $25 a share to mere pennies at the bottom. The failure of its Washington wildcat didn't do it any favors either, though shares temporarily spiked on the prospects. While its auditor expressed doubts about its ability to remain a going concern, the presence of billionaire investor Kirk Kerkorian, whose Tracinda investment vehicle owns a third of Delta's stock, in addition to its pursuit of possible strategic alternatives gives investors hope they'll be able to extract some value out of the oil and gas developer.

I wouldn't expect too much out of Delta anytime soon, however. Everyone seems to hate natural gas these days, with EOG Resources (NYSE: EOG) divesting assets and SandRidge Energy (NYSE: SD) saying it can make much more money in oil than in gas. Delta's own drilling operations have been severely hampered by debt covenants restricting capital expenditures to just $10 million in the last two quarters, and to only $5 million in the coming quarter ending June 30. Partnerships like the one it signed with Opon International may help it expand operations somewhat (and the cash influx will help liquidity) but it'll likely be only a pale shadow of its former self.

Yet it's just those kinds of joint operations that give CAPS member Rihanna the courage to predict an increase in how the market values Delta over the long haul:

thing I don't understand here is their Market cap is 427 million or so as I write this, while Opon has decided to offer them 400 million dollars or so for a 37.8% stake in Vega, which to Delta is nothing if you pull up a chart and see how much other land these guys actually own in various parts of the U.S, the Market cap on this should be well over 1 billion, if not close to 2 billion...

Going into reverse
Sometimes companies do a reverse split for strategic reasons. Biglari Holdings (NYSE: BH) (formerly known as Steak n Shake) completed a 1-for-20 reverse split to scare off investors who don't like high-priced stocks (its shares trade in excess of $400 each). Most of the time it's because a company is in severe financial distress.

NCI Building Systems had to complete a 1-for-5 reverse split to prop up its shares as the commercial and industrial real estate market looked ready to implode. But it reported a narrower quarterly loss last month, and coupled with more confidence in manufacturing and housing, shares are now about 45% higher than where they were just after the reverse split.

More than 90% of those rating the building components manufacturer believe it will continue to beat the market, no doubt believing as MGWinvestments does that it's an otherwise solid company: "Fundamentaly sound company. Was hit very hard by the economy. Will rebound nicely and regain some of its value. Company is a low risk high reward investment."

Rolling down the highway
Real estate services provider E-House (NYSE: EJ) was just one Chinese company benefiting from the huge influx of government stimulus spending, soaring more than 300% since the end of 2008 as the government poured money into the sector. While that in part caused property prices to boom since 2001, curbs on lending are coming and are being called some of the "most draconian measures" in history, according to Deutsche Bank.

Chinese energy-saving products maker SmartHeat may bear the brunt of proposed government restrictions or any reductions in government initiatives, as it said the 153% increase in revenues it enjoyed in 2009 was a result of funding by government spending. CAPS members aren't worried though, and All-Star mrindependent thinks the potential rewards outweigh the risks:

Looks like there is more upside than downside for this young chinese manufacturer of plate heat exchanges and other temperature related doodads. Trading at almost 50% off it 52 week high due to recent minor earnings disappointments. 

Have half a mind
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The Fool owns shares of Biglari Holdings. 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.