Not my words. Those were Warren Buffett's. Back in 1974. He turned out to be right.

Earlier this decade, he warned about the insane valuations during the Internet bubble and the dangers of derivatives. Correct, and correct again.

Last October, he wrote an op-ed piece in The New York Timesurging investors to start buying stocks. In addition to his recent shopping spreeon behalf of his company, Berkshire Hathaway , he started buying up stocks for his personal account. Though the latest quarter saw him focusing on foreign debt securities, he still picked up shares in Becton Dickinson and Johnson & Johnson .

The day Buffett penned his Timespiece, the S&P 500 closed around 950. Almost a year, a big dip, and a big rally later, we're sitting higher ... but not that much (around 12%) higher.

Certainly, we should follow Buffett's lead, right?

Not so fast.

Despite a newly growing GDP, the economic numbers are ugly. Unemployment is just under 10%, the next decade's annual deficits are projected to almost double our already $11 trillion-plus national debt, and consumer confidence is still "eh." Yet we've just seen the market rise over 50% in half a year. Yikes!

Who's right? Is now another time to invest and get rich? Or is the market a sucker's bet?

Buffett vs. the numbers
Before I answer those questions, let's be clear. This isn't a market-timing discussion. We Fools believe there's no proven way to consistently time the market. Even Buffett admits that he can't predict the short-term movements of the market. He thinks in years and decades, not days and months. After all, he's the guy whose favorite holding period is forever.

Back to the question at hand: Don't be surprised if both the numbers andBuffett are right. The economy and the stock market could get worse from here, but it could still be a great time to invest and get rich.

Huh?

Remember, since we can't time the market, we're talking only about money you can keep in the market for the long term. Unlike Jim Cramer, we Fools have alwayssaid that money you need in the next three to five years should never be in the stock market. As the last year has shown, it's just too darn volatile for money you need in the short term. 

So, even if the gloomy numbers are right -- if the economy worsens, and the stock market drops again over the next year or two -- we could be looking back three to five years from now, thinking that now was a great time to invest and get rich.

OK, but how bad could it get?
Before you start putting some of your idle cash into stocks, know that it could get a whole lot worse all over again. Fellow Fool Morgan Housel showed just how much worse in " How Low Can Stocks Go?"

Long story short, the S&P 500 has had long stretches in which it has seen average price-to-earnings ratios of around 8. Even after the freefall we've seen (but after this recent rally), the S&P 500's average P/E (for companies with positive earnings) is 78. Wow.

Here's a place to start
Where, then, can we see some of this market cheapness that Buffett wrote about? Not so much in forward earnings -- Birinyi Associates forecasts the S&P 500's forward P/E ratio at 18. Of course, I don't trust analyst earnings estimatesto begin with, and I certainly don't trust them in the current environment.

No, it's at the individual-stock level where I warm up. Though the pickings are slimmer than a few months ago, when you could get quality companies like Visa (NYSE: V), Starbucks (Nasdaq: SBUX), and Microsoft (Nasdaq: MSFT) for half of today's price, we still have big-time companies trading at low P/E ratios. When I start seeing P/E ratios in the neighborhood of single digits, I get very interested. Take a look at these companies:

Company

P/E Ratio

Chevron (NYSE: CVX)

9.3

Altria (NYSE: MO)

11.9

Merck (NYSE: MRK) Continued...