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 that 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

JA Solar (Nasdaq: JASO)

****

50%

Frontlines (NYSE: FRO)

****

57%

Alexza Pharmaceuticals (Nasdaq: ALXA)

****

58%

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.

Sunburn for solar stocks
While the CAPS Solar Power sector is up 24% over the past year, the stocks comprising the niche are down sharply over the past month. Concerns about subsidies are already baked into the price of these stocks, as it's been a known quantity for some time and inventory oversupply has been a growing worry. But just as the industry is approaching a point of cost-per-watt parity, analysts are worrying about pricing sustainability.

Specifically SunPower (Nasdaq: SPWRA) and First Solar (Nasdaq: FSLR) were identified as being particularly susceptible to not being able to maintain premium price advantages. But investors aren't so sure. CAPS member Onigato looks at situations like the one in Germany as an opportunity for solar shops like JA Solar to prosper: "A solid seeming company, with a good probable future if Germany goes through with their plans to remove nuclear from their power grids while maintaining clean energy. Trading at a TTM 3.5 at the time of this recommendation, with the revenue stream to back up future growth, this looks like a good pick for the long run."

Perhaps with good reason. Germany accounted for more than 18% of JA Solar's revenues last year, making it the company's biggest market outside China, where it made half of its sales. Let us know on the JA Solar CAPS page whether the Chinese solar shop will burn investors or shine brightly.

Going down with his ship
It's tough to be bullish about an industry when even the chairman of one of the leading players thinks an already lousy business environment is likely to get even worse. John Fredriksen, head of the leading oil-tanker company Frontline, recently said he's looking for the industry to "collapse" within the next two years.

Mind you, this is already an industry where earnings have plummeted more than 80%, operators have increasingly anchored their ships, and they've had to resort to "slow steaming" strategies to compensate for the glut of ships on the high seas. Frontline has a big weighting in Bloomberg's tanker index, second only to Teekay (NYSE: TK), which ships 10% of all the oil supply on the world's oceans.

CAPS member Catfish136 admits that the shipping industry is terrible but finds that Frontline should make it to the leeward side of the island before the worst of the storm hits: "Best of companies doing business in the crappy shipping industry. This one will survive the 'rough seas' ahead in this global economy."

Only you can determine whether Frontline is right for your portfolio, so add it to your watchlist and have all the Foolish news and analysis about it aggregated for you in one place. Then let us know on the Frontline CAPS page or in the comments section below whether you think the shipping industry is ready to sink.

Fixing this pharma stock
Bipolar-drug maker Alexza Pharmaceuticals is flying beneath the radar of most investors, no doubt because of the setback it suffered last October, when the FDA said the drug it's looking to market with Valeant Pharmaceuticals (NYSE: VRX) needed to address a series of concerns before it was ready for review. It might pop up on the screen soon, however, as the company readies to resubmit AZ-004 next month.

Assuming all goes well with the FDA, Alexza made sure it had sufficient funds on hand to carry it through its PDUFA date early in 2012 by raising cash earlier this year. Although AZ-004 is its lead candidate, Alexza has more than just the bipolar therapy in its arsenal. Basing a screen on its proprietary Staccato delivery system, Alexza has identified some 200 drug compounds that could benefit from the aerosol technology for vaporizing a drug. It's moving forward on testing a handful of them right now, and CAPS member garypalys is enamored with the pipeline.

Monitor how well Alexza's investment in its technology works out by adding the stock to the Fool's free portfolio tracker.

Have half a mind
Sign up today for the completely free CAPS service, and tell us whether these stocks are twice as good at half the price.

Motley Fool newsletter services have recommended buying shares of First Solar. Try any of our Foolish newsletter services free for 30 days. We Fools don't all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors.

Fool contributor Rich Duprey has no financial position in any of the stocks mentioned in this article. You can see his holdings. The Motley Fool has a disclosure policy