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 cry about 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 still earn top honors from our investor-intelligence database. Consider it a BOGO sale on stocks.

Stock

CAPS Rating

% Off 52-Week High

Clean Energy Fuels (NASDAQ:CLNE)

*****

78%

CME Group (NASDAQ:CME)

*****

72%

OmniVision Technologies (NASDAQ:OVTI)

*****

71%

ShengdaTech (NASDAQ:SDTH)

*****

75%

Titanium Metals (NYSE:TIE)

*****

77%

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 three: They're small
It's little surprise, really, to find shares of CME Group, a derivatives exchange, sliding along with commodities prices. CAPS member JFkeiko considers it a bull market stock that will recover.

This stock will explode to the upside as soon as the financial/housing crisis dies down....This is a bull market stock, so when the bulls show their strength again....look out.... [Edited to remove all caps]

Assuming that General Motors (NYSE:GM) and Ford (NYSE:F) survive in some form or another, eventually there should be quite a bit of demand for natural gas-powered cars to boost Clean Energy Fuels. CAPS member SouthCarolina thinks that even with the demise of one or both of them, foreign car makers will also be developing more models, so natural gas can't be ruled out.

I have been watching this company for over a year now. While I am not a fan of T. [Boone] Pickens - I think this company is going to have great success. They are very proactive about creating new or taking over existing fueling stations … With … our domestic car production companies suffering so badly (GMC said today that they are fairly certain that they don't have enough cash on hand to keep operations going through the end of the year) - natural gas [is] a fantastic alternative. It really doesn't matter that electric / hydrogen / whatever is competing with natural gas as an alternative energy because the technology for natural gas is already developed and easier to implement quicker for car production operations.

Image sensor technology is expected to grow to an $11.7 billion industry by 2012, according to the market researchers at Global Industry Analysts. Among those positioned to benefit from that is OmniVision Technologies; CAPS member gcstrong wrote at the beginning of last month that it will continue to win design contracts.

Trading below 10, with 6 dollars cash per share. Conservative EPS estimate of .70 cents next year. New products in the pipeline, and new production technology should put them in place for future design wins in '09. Major competitor [Micron Technology] is dreadfully run company.

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.

Titanium Metals is a Motley Fool Stock Advisor pick. Try any of our Foolish newsletters 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. The Motley Fool has a disclosure policy.