Guy Spier, a famous value investor, once said that one of the best ways to follow a company is by buying one share of it. After all, once you own a share, even one share, you have skin in the game. This isn't easy if you're interested in a $3,000 stock like Amazon or even if you wanted to pick up shares of Snowflake during its initial offering of $245 a share on Wednesday. 

Double-digit-priced stocks, especially those below $20, can provide a low-cost entry point into some spectacular opportunities. Here are three stocks priced below $20 a share that are worth buying now.

A virtual bull climbs a candlestick graph, representing a rising stock market.

Image source: Getty Images.

Virgin Galactic

Starting this list is the latest popular and largely unproven space stock Virgin Galactic (NYSE:SPCE). Virgin Galactic trades at less than $17.50 a share, a low entry point for a potentially disrupting growth stock.

The company's strategy is simple enough. It wants to establish a commercial spaceflight program capable of competing in the emerging space tourism and travel industry. Its three existing aircraft comprise its starting fleet, but it also has two more under construction. 

Virgin Galactic hopes to begin sending passengers into space in the first half of 2021. Given the cost and high barriers to entry of this brand new industry, Virgin Galactic's valuation is based almost entirely on its vision, not what it's earning today. In fact, the company posted $0 in revenue last quarter. 

Despite being largely unproven, Virgin Galactic has the potential to define a new industry. 2021 could be a volatile year if its plans get delayed, but the stock could very well double if its vision starts to become more of a reality.

Equinor

Equinor (NYSE:EQNR), formerly known as Statoil, is the largest oil and gas company in Norway. It's also the best-performing oil major so far this year, albeit at a negative total return.

EQNR Total Return Price Chart

EQNR Total Return Price data by YCharts

Despite achieving record oil production and decent earnings and cash flow in its first quarter of 2020, Equinor fell victim to the challenging collapse in oil and gas prices that resulted in negative free cash flow (FCF) and next to no profits for its second quarter. 

It wasn't a great quarter, but Equinor was able to keep its balance sheet at reasonable levels, all things considered. Its efforts to slash the dividend by two-thirds, reduce spending, and suspend share buybacks are likely necessary to give the company breathing room to get through this downturn. 

Although it looks bad now, it's worth noting that Equinor is the dominant player in the North Sea, having reduced its breakeven price per barrel to allow the company to continue drilling for oil. But the North Sea is a mature field that Equinor can't count on forever. Its solution: offshore wind

Equinor is an OK oil and gas company, but it could become a leading offshore wind company. The company's new CEO, Anders Opedal, will take control on Nov. 2, and has pledged that renewable energy will be a central focus for Equinor going forward.

Given Equinor's experience with offshore technology, its deep pockets, and its first-mover advantage into this niche renewable space, the company seems to be one of the best-positioned oil majors to turn into a renewable energy stock. Equinor trades for under $16 a share at the time of this writing.

Kinder Morgan

Shares of pipeline giant Kinder Morgan (NYSE:KMI) go for under $13.50 at the time of this writing.

Like Equinor, Kinder Morgan is an energy giant. Forty percent of natural gas consumed in the U.S. passes through its pipelines, and it has plans to build more.

Kinder Morgan's focus on natural gas has kept it mostly insulated from the volatility in energy markets. The company's use of long-term contracts gives it predictable revenue and operating cash flow. As a result, it only expects a 9% decrease in EBITDA and an 11% decrease in distributable cash flow (DCF) for 2020, which is manageable. In fact, Kinder Morgan's FCF is well ahead of its dividend obligation.

KMI Free Cash Flow Per Share (Quarterly) Chart

KMI Free Cash Flow Per Share (Quarterly) data by YCharts

Management has stated it's going to refrain from merger and acquisition activity and focus on paying a consistent and growing dividend. Kinder Morgan's dividend yields 8.1% at the time of this writing. The fact that Kinder Morgan can back up this dividend with cash during a challenging time for the oil and gas industry is a testament to its sound business model. 

A dynamic trio

Virgin Galactic, Equinor, and Kinder Morgan offer completely different approaches to buying a stock under $20. Virgin Galactic is a risky, but potentially lucrative, growth stock. Equinor is an established oil major that's in hot pursuit of a new identity. Kinder Morgan is a stodgy natural gas stock that has the numbers to back up its over-8% yield. Buying all three stocks would cost you less than $50 and could prove to make you money in different ways over the longer term.