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 top five-star honors from our investor-intelligence database. Consider it a BOGO sale on stocks.

Stock

CAPS Rating (out of 5)

% Off 52-Week High

Arch Coal (NYSE:ACI)

*****

58%

Century Aluminum (NASDAQ:CENX)

****

74%

Crosstex Energy (NASDAQ:XTXI)

****

87%

Focus Media (NASDAQ:FMCN)

*****

71%

Paragon Shipping (NASDAQ:PRGN)

*****

67%

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
If you want a good indication of where global trade is heading, keep an eye on the direction the Baltic Dry Index is moving. Measuring the bulk shipping rates on routes across the world, the BDI is a good proxy for how international trade partners are faring.

After riding a tsunami higher through most of 2008, the index capsized late in the year, and it's found itself floundering for the most part ever since. Although shipping mounted a feeble comeback, China's decision to curb industrial production may mean that the recovery we saw taking shape with Navios Maritime (NYSE:NM) might give shippers that sinking feeling again.

For example, despite beating earnings expectations, Paragon Shipping hasn't fared so well. Its shares trade as flat as becalmed seas. Shipping rates for Paragon continue to erode, down to $36,800 from far more than $39,000 at the end of the fourth quarter; at that time, it also cut its dividend to just $0.05 a share.

Some investors don't see this as a problem, though. CAPS member Ecomike still finds Paragon quite attractive:

PRGN has steady, rising earnings, and a solid 5% dividend at this price, that is 10% of last years dividend. PE is rediculously low at near 2:1. Compare it to NMM, or NM, which I also own, and hold at currently higher PEs. It is a great buy at this price. Should see $6-$8 before the end of this year.

The 16 companies comprising the CAPS Dry Bulk Shipping sector have also posted fairly flat returns over the past month, but as a whole, they're off more than 60% this year.

Out of gas
The stock with the worst performance on our list is Crosstex Energy, a natural gas pipeline business operator. You'd figure that running a pipeline to transport gas would be like collecting fees for every car that crosses a toll bridge, and in normal times, you'd be right. But these aren't normal times. Natural gas prices remain severely depressed, testing lows we haven't seen since the early part of this decade.

That, and the need to service some significant debt, has forced Crosstex Energy to lighten up on some of its assets. It sold some midstream natural gas assets in Texas, Mississippi, and Alabama to a private equity investor at the start of last month. At the end of the month, it followed that up by selling its gas treatment business to Kinder Morgan (NYSE:KMP) for $266 million.

Top-rated CAPS All-Star member MJKpayday still finds the natural gas sector a wonderful place to drill for beaten-up players:

Natural gas is still cheap and may be for so along time. I'm trying to round up several potential nat gas ideas and this is one.

It's a partnership that covers several aspects of natural gas and liquid natural gas. If natural gas prices go up so will Crosstex. I need to research management and the implications of a partnership before moving forward.

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.

Precision Drilling is a Motley Fool Global Gains recommendation. The Fool owns shares of CapitalSource. Try any of our Foolish newsletter services today, free for 30 days.

Fool contributor Rich Duprey owns shares of Nasdaq OMX but does not have a financial position in any of the other stocks mentioned in this article. You can see his holdings here. Test drive the Motley Fool's full-size disclosure policy.