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

Stock

CAPS Rating
(5 max)

% Off 52-Week High

Akamai (NASDAQ:AKAM)

*****

56%

American Oriental Bioengineering (NYSE:AOB)

*****

70%

Mosaic (NYSE:MOS)

****

74%

Petrobras (NYSE:PBR)

*****

64%

ReneSola (NYSE:SOL)

*****

92%

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
Chinese solar wafer maker ReneSola is hitting a double bottom of sorts, but it's not what you might think. In technical analysis, a "double bottom" is when a stock price chart shows two consecutive drops bookending a sharp rise in price. It's a bullish signal that resembles the letter "W" and may represent a reversal of fortunes for the company. But ReneSola's double bottom is something else.

Not only has the wafer maker seen its stock hit a point that's more than 90% below its 52-week high, but its current price is also more than 50% below the mini-rally it enjoyed at the beginning of the year. Like ReneSola, LDK Solar (NYSE:LDK) surged as 2009 got under way in the midst of some insane bacchanalia that gripped the industry, but both have since given back those gains and more.

Even solar panel makers like Suntech Power (NYSE:STP) have been on the skein, with shares getting halved in the process. Analysts say inventories are piling up in China, where more than 140 manufacturers of solar-grade wafers are located. With many operating at less than half capacity, the low selling prices plaguing the industry are reinforced. Wafer shipments are expected to reach almost 2,100 megawatts, almost double the number from a year ago, but this still represents a significant slide in growth rates compared to last year. Thus, investors should not be surprised if margins come under pressure this time around.

If you look just at the debt ReneSola has packed on recently, you'll miss the significant profit it realized from a joint venture it divested from, as well as the lines of credit it previously secured that it planned to use for expansion. While those plans are in part postponed, other analysts contend that demand has bottomed and the falling average selling prices mean the industry could approach grid parity. Not that 2009 won't be difficult for ReneSola and other industry players, but the worst may be behind them, and a recovery may start next year.

That "better times will come" attitude is sustaining some investors like CAPS member jdev5, who finds ReneSola to be fundamentally sound. With an exceptionally cheap share price, it offers better potential than some bigger, better-known names, says this investor:

once trading at a high over 29, trading over 9 in the last few months this is a bargain price to pick up this little gem. Solid fundamentals lie at the heart of this company and the price will net you a ton of shares compared to bigger names like [Apple] or [Google]. It won't bounce back today or even tomorrow, but give it a few months and watch the wealth grow.

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.