You don't need to have a pile of money to start investing. If the whole idea is to buy low and sell high, it would stand to reason that some of the best investments are still cheap. The key is to spot them while they are cheap and watch your money grow at a rate that could far outpace the rate of return on more expensive investments.
Silver
Gold is pretty expensive, but silver is a great way to invest in the precious metals market without breaking the bank. You can buy a one oz. pure silver American Eagle coin for less than the price of two movie tickets and popcorn. You could then stash it away in a safe place and wait for it to appreciate in value.
Treasury Bills
The current yield on a four week Treasury bill issued by the U.S. government is practically zero, but if you want a safe place to invest money and also play a small role in supporting the country, you can buy Treasury bills with as little as $100 in capital. They are offered by the federal government with maturities that range from four weeks to one year.
Penny Stocks
Penny stocks are cheap and often risky securities that are sold in the over-the-counter market. You can win or lose big with penny stocks. For instance, with a stock priced at 10 cents a share, you can buy 1,000 shares for $100. Every time its price goes up or down a single penny, you make or lose $10.