Penny stocks are one way to double your money -- but that approach is fraught with risk, There are equally shiny and far safer opportunities trading at the other end of the price spectrum, too. I call 'em "three-digit stocks," yet if they're anything like Berkshire Hathaway, they can trade in the four-, five-, and six-digit range, too.

penny stock might not be a good buy simply because it's cheap, and a three-digit stock shouldn't scare you away just because it carries a hefty price tag. Handsome is as handsome does. Let's check in with the Motley Fool CAPS community, to see which of the high-priced stocks below earn the greatest confidence from our investor-intelligence database:

Stock

CAPS Rating (out of 5)

3-Digit Price

Return on Capital, TTM

AutoZone (NYSE: AZO)

*

$230.63

36.5%

AMBEV (NYSE: ABV)

*****

$125.89

18.7%

F5 Networks (Nasdaq: FFIV)

**

$105.89

14.1%

Source: Capital IQ, a division of Standard & Poor's; Motley Fool CAPS.

Just because these stocks are purring is no reason to jump into them blindly. Catching a tiger by the tail -- or a knife falling from on high -- can leave you scratched and bleeding. That's why we recommend you use this list as a launch pad for your own research and analysis.

Highfalutin' honeys
In today's frugal times, it doesn't take a penny-pinching millionaire's mindset to see the value of buying a used car. That helps explain why used-car dealer chain CarMax (NYSE: KMX) reported analyst-beating earnings, even as used-car prices rose to record highs. It's also why AutoZone is on a tear: More people are fixing their cars instead of trading them in. AutoZone's shares are trading almost 50% higher this year. Even troubled repair shop Pep Boys was able to record a 3% increase in sales, as comps rose almost 2% over last year.

CAPS member 2win2 says the current economy is a good catalyst for AutoZone's future growth, while cher46 expects the home-mechanic mindset to flourish:

I work for Autozone....I have faith in my company and that they will continue to do all the right things to keep making the company grow and stay number 1. I also believe that most people will keep their cars longer and repair them themselves as needed.

Not so rough
Forget China: The smart money is looking for hot investments in Brazil. Institutional investors have been pouring money into businesses there, including sugar producer Cosan (NYSE: CZZ), low-cost airline GOL Linhas, and beer distributor AMBEV.

If you're going to invest, however, do so with care. Brazil is slowly abandoning its fragile market economy in favor of greater government control. Petrobras (NYSE: PBR) found that out when the government took control of more than half of the oil company, overcharging the company for oil reserves in exchange for those shares.

Roughly 97% of the CAPS members who've rated AMBEV indicate it will outperform the market. Our community seems to be wagering that the Brazilian government won't get so drunk on power that it kills the cash cow this alcoholic-beverages distributor has become. Let us know in the comments section below, or on the AMBEV CAPS page, whether you think this is still a heady opportunity.

Triple-digit titans
Tech stocks are in the grip of merger mania. Oracle (Nasdaq: ORCL) has publicly announced that it wants to snap up as many businesses as possible, and IBM, HP, Dell, and Cisco all want in on the action, too. They all happen to be high on analysts' list of potential buyers for F5 Networks. The company said a prospective purchaser approached it last year; its shares have surged by 175% over the last 12 months.

Even so, after comparing its valuation to next year's earnings, analysts say it trades at a discount to Riverbed Technology and Acme Packet. But highly rated CAPS All-Star member stockgripes thinks the network-optimization specialist has gotten ahead of itself: "The stock has run too fast for it's own good. There are other companies in this space, like Cisco, HP, etc."

Stay on top of F5 Networks by adding it to your My Watchlist page. We'll aggregate all our Foolish coverage of the company for you in one convenient place.

Count to 10
These three-digit stocks might be on their way to even higher valuations. That's why it pays to start your own research in 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.

Petroleo Brasileiro is a Motley Fool Income Investor recommendation. The Fool has written a bull call spread on Cisco Systems. The Fool owns shares of IBM and Oracle. Try any of our Foolish newsletter services free for 30 days.

True to its name, The Motley Fool is made up of a motley assortment of writers and analysts, each with a unique perspective; sometimes we agree, sometimes we disagree, but we all believe in the power of learning from each other through our Foolish community. The Motley Fool has a disclosure policy.

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.