There's one good thing about major market sell-offs. Actually, it's a great thing. They give investors an opportunity to buy some stocks at bargain prices.

We asked three Motley Fool contributors to select dirt-cheap stocks that you can buy right now. Here's why they chose BioNTech (BNTX 1.26%), Pfizer (PFE 0.72%), and Viatris (VTRS 1.27%).

A smiling person looking at a touchscreen tablet.

Image source: Getty Images.

Trading at a minuscule earnings multiple 

David Jagielski (BioNTech): Often investors discount a stock that may seem like it is punching above its weight class, on the assumption that it may struggle down the road. BioNTech's forward price-to-earnings multiple of around 3.8 certainly suggests that investors are perhaps not taking the growth stock seriously. 

But those investors would be mistaken. BioNTech has what looks to be an excellent partnership with pharma giant Pfizer. The two companies joined forces to create the highly successful COVID-19 vaccine, BNT162b2. And now, they're also working on a shingles vaccine based on messenger RNA (mRNA) technology with clinical studies targeted for later this year.

In addition to the shingles vaccine, trials will commence for products that are focused on malaria, tuberculosis, and the herpes simplex virus (type 2). BioNTech also has a promising oncology pipeline that features 20 ongoing clinical trials.

The company is generating tons of cash right now. That will help fund all these opportunities and possibly even enable BioNTech to take on an acquisition in the future to help accelerate its growth. During the first three months of 2022, the company reported positive operating cash flow of more than 4 billion euros. And as of the end of the period, its cash and cash equivalents balance stood at 6.2 billion euros.

BioNTech's pre-tax profit in the first quarter was 79% of sales, suggesting that the business runs a tight ship and has been doing good at keeping its costs down. That can go a long way in leading to significant profit growth in the future, potentially resulting in great returns for investors.

BioNTech's business is flush with opportunities and is efficiently run. Smart investors know the stock could be one heck of a deal right now.

Soaring revenue but an inexpensive valuation

Keith Speights (Pfizer): I think that BioNTech's partner, Pfizer, could present an even better inexpensive alternative for investors. Shares of the pharma giant currently trade at close to seven times expected earnings.

Unlike BioNTech, though, Pfizer isn't solely dependent on one product to generate those earnings. The company's lineup includes at least nine drugs or vaccines on track to produce sales of $1 billion or more this year.

Overall, Pfizer appears to be poised to rake in close to $100 billion in 2022. That would set the record for the most revenue ever made by a pharmaceutical company. 

Granted, Pfizer's growth these days is primarily driven by its COVID-19 vaccine and by its oral COVID-19 therapy, Paxlovid. But even factoring these programs out of the mix, the company expects to deliver double-digit adjusted earnings-per-share growth through 2025.

What about beyond that point? Several of Pfizer's top products will lose exclusivity in the second half of the decade. However, the company still expects to continue growing on both the top and bottom lines.

One key reason behind this optimistic outlook is Pfizer's acquisition strategy. The company has already bought Trillium Therapeutics and Arena Pharmaceuticals over the past 12 months. It just announced plans to acquire Biohaven Pharmaceuticals to pick up its migraine drugs Nurtec and zavegepant. 

As an added bonus, Pfizer offers an attractive dividend yield of 3.2%. I expect the company to continue increasing its dividend payout in the future.

"Dirt-cheap" doesn't begin to describe this stock

Prosper Junior Bakiny (Viatris): In today's challenging environment, investors are increasingly seeking companies that look attractively valued. And in that department, it is hard to do better than generic drug manufacturer Viatris. The company's forward price-to-earnings (P/E) ratio of less than 3.1 seems like a bargain by almost any metric. The average forward P/E for the pharmaceutical industry stands at 12.8, while that of the S&P 500 is 19.4. 

Sure, the market may be overlooking Viatris for good reasons. The company is dealing with various issues, including sluggish revenue growth.

But there are reasons to be optimistic, too. Viatris remains one of the largest generic drug manufacturers in the world. The company's products don't benefit from patents, but it is increasingly looking to advance complex generics. These products typically have less competition on the market and can help boost Viatris' revenue growth in the coming years.

Meanwhile, the company is looking to improve its balance sheet, notably by paying down its debt. Viatris set a goal to pay down $2 billion in debt by the end of 2022. It's currently on track to achieve that goal.

One more significant reason to consider investing in Viatris is the dividend. The company currently offers a juicy yield of 4.6%-- more than triple the S&P 500's yield of 1.37%. With a commitment to continue to reward shareholders through dividend increases, income-seeking investors will find what they are looking for with Viatris.

Some may think that Viatris' business is pretty boring overall. But boring may be just what investors need, given how volatile the market has been all year long. And at current levels, Viatris looks like a steal for those investors willing to be patient.