Starbucks (SBUX) pulled off a textbook turnaround, multiplying its stock price five times since early 2009.

Investors made similar money over that stretch in shares of Boston Beer (SAM), maker of Samuel Adams Boston Lager.

But both stocks may now have gotten ahead of themselves, and investors should look for cheaper fare.

Starbucks addressed slipping sales growth in recent years by closing underperforming U.S. stores and opening new ones in thriving overseas markets. It found ways to grow revenue without sinking large sums into expansion by, for example, selling brewed coffee through convenience stores and pushing more beans through grocers. (It even tackled this coffee snob's biggest gripe, overroasting, by introducing a "blonde roast" coffee.)

Boston Beer, on the other hand, grew through the global financial crisis without a hiccup, thanks to strong demand in a U.S. market it arguably created: craft (which is to say, good) beer.

There's much to like about both companies. Margins are plump, and more important, so are returns on money that management has invested in the businesses. And coffee and beer are relatively affordable pleasures that can sell well even during periods of slow economic growth and high unemployment.

But Starbucks shares now trade at about 29 times trailing earnings and Boston Beer, at 27 times earnings. That compares with 15 times trailing earnings for the S&P Composite 1500 index of large, midsize and small companies.

The popularity of these stocks speaks to investor demand for growth at a time when growth is scarce. Earnings for S&P 500 companies are expected to decline year-over-year this quarter, for the first time since 2009. It also illustrates that demand is high for shares of companies that can resist recession.

The lofty valuations may also be a result of a Peter Lynch teaching taken to the extreme. The famed Fidelity stock-picker advised investors to buy what they know -- to shun overly complex businesses and instead look to ones they experience in everyday life. But if investors aren't careful enough about price, the approach can make the most familiar companies expensive.

The recent slowdown in U.S. corporate earnings suggests forecasts will have to be brought down. Wall Street expects S&P 500 earnings to increase more than 13% next year, after a 5% gain this year; either it's watching economic data the rest of the world doesn't have, or the projections are outdated.

If earnings estimates are to fall, stocks that look expensive relative to earnings could be hit harder than others. Companies like Intel (INTC), Aetna (AET), Caterpillar (CAT) and Chevron (CVX) aren't the trendiest names around, but they all sell for 10 times earnings or less and have decent dividends. The prices suggest low expectations, something that could come in handy if corporate results broadly disappoint.