With the S&P 500 down 23% this year, investors are understandably lamenting the disappearance of their gains. Yet, some also see a silver lining in the form of great stocks on sale. For those who can afford to do so, now may be a great opportunity to find stocks that could reward them many times over by the time they need the money.

PayPal (PYPL 0.64%), Airbnb (ABNB 1.17%), and Costco Wholesale (COST 0.17%) are three great stocks to buy with $5,000 in the market sell-off now. Let's take a closer look at them.

Get ready for something big

PayPal was one of the first tech stocks to get crushed in the current sell-off after it released a disappointing 2022 outlook in its fourth-quarter earnings report. There's no other way to look at it; things are slowing down. That's not terribly surprising after it posted its best quarters ever in the early stages of the pandemic. Macro trends are shifting at a rapid pace, and PayPal did a complete turn from being at a peak to now slowing down.

The reason to buy isn't just for its cheap price, but that's a big factor. PayPal stock is trading at its lowest valuation ever at only 24 times trailing 12-month earnings and a price-to-earnings growth ratio of less than one, which suggests that the stock is undervalued at the current price. 

But the cheap valuation is meaningless unless the company is going to continue growing, and that's why PayPal looks compelling right now. It's likely to post lower growth with rising inflation rates and slower spending. But e-commerce -- the company's bread and butter -- is still increasing. PayPal is well-positioned to take a big bite out of that for many years. 

The 2022 first quarter was far from a letdown. Total payment volume increased 13% year over year, and revenue increased 7%. One caveat is that in 2021 PayPal ended its deal with eBay to provide payments services on its site -- and so taking that out, revenue grew 15%. That was on top of a 31% increase last year, the company's strongest first quarter ever.

PayPal also added 2.4 million net new active customers in Q1 2022 and expects 10 million for the full year. The updated guidance was 11% to 13% revenue growth for fiscal 2022. Looking at the big picture, the quarter was strong. 

PayPal stock is down 61% this year, and it may stay low until the economy is in better shape. But you don't have to wait for the stock to get any lower to lock in this deal.

The travel rebound is happening

Airbnb has been posting phenomenal growth over the past year, and the reason its stock is down 40% in 2022 appears to be a combination of a high valuation and the general tech sell-off. Even at this price, the stock trades at a forward one-year price-to-earnings ratio of 55. But growth stocks with excellent potential tend to trade at a premium, and Airbnb is a company with great long-term prospects. 

The company demonstrated this in Q1 2022 with another excellent performance. Revenue rose 70% year over year to $1.5 billion, and nights and experiences booked increased 59%. I would note that revenue is outpacing bookings, which means it's making more money per booking overall. There was a net loss of $19 million after several quarters of profits, but it was an improvement from more than $1 billion last year. Free cash flow was $1.2 billion, almost double last year's, as the business is flourishing.

And this looks like only the beginning. Despite multiple headwinds in the form of inflation, high travel costs, and geopolitical challenges, bookings keep going up. People are simply itching to travel, and Airbnb gives travelers flexible options so they can get away, whether it's upstate, interstate, or overseas. At the same time, these potential threats may begin to hurt business growth at some point, especially if they're protracted, which is the way it's looking right now.

However, the company has shown that it can withstand short-term pressures and remain resilient. Long-term, its prospects look robust. It's able to offer services that meet shifting trends, such as longer stays induced by the work-from-home movement and migration to smaller cities. The fact that it's agile enough to easily move in that direction portends well for when trends shift again. This is a stock with so much upside, and now is a great time to buy.

Where Americans shop when there's inflation

Americans, and many other people around the globe, shop at Costco, inflation or not, to benefit from potentially big savings. But when prices go up and people are penny-pinching, shoppers have even more reason to head over to the company's huge warehouses where prices are marked up by razor-thin margins that are much narrower than competitors'. But what Costco doesn't get in markups, it gets in volume, and so far, sales have skyrocketed in 2022.

The third-quarter earnings report was hotly anticipated after rivals Target and Walmart demonstrated sluggish growth. But Costco showed no signs of slowing down with sales still elevated from before the pandemic. Revenue increased more than 16% year over year, with earnings per share of $3.05 versus $2.75 last year. Margins were, understandably, slightly lower year over year. But earnings from membership fees increased to nearly $1 billion, with a worldwide renewal rate of around 90%. 

So far, this is continuing into the fourth quarter. May sales were up nearly 17% over last year. In this tight atmosphere, it's even less likely that members will give up their Costco cards.

Costco stock typically trades at a bit of a premium for precisely this reason. But now that it's down 20% this year, shares are trading at a multiple of 36 times trailing 12-month earnings. That's still not cheap, but it's a discount that's worth considering. Costco is a no-brainer stock to buy that does well under pressure and always -- and that's why it consistently outperforms the market.