Well, the last few weeks have been some of the most painful ASX investors have had to endure for quite some time. Over the past few years, ASX investors have probably become used to their ASX 200 stocks 'just going up'.

After all, the S&P/ASX 200 Index (ASX: XJO) rose by a healthy 7.88% or so in 2023, and by another 7.5% in 2024. Last year, the index also hit dozens of new all-time record highs.

But just today, the ASX 200 dropped below 8,000 points for the first time in roughly five months. Since hitting its latest high of 8,615.2 points in mid-February, the index has now retreated by a sizable 7.35% or so.

Not quite a correction just yet, but a sell-off nonetheless.

Now, sell-offs like this are never fun for investors. But they do give us the chance to buy shares at cheaper prices, which is never a bad thing.

There are two ASX 200 shares that I've had my eye on for a while now. They are still not quite cheap enough for me to buy today, but if the market keeps dropping, there will come a point where I'll be loading up the truck.

2 ASX 200 shares that I'll buy if the market keeps selling

REA Group Ltd (ASX: REA)

First up, we have property stock REA Group. REA is the leading property classifieds stock in Australia, thanks to its flagship asset, the uber-popular realestate.com.au site.

REA has profited enormously from the growing housing market in Australia over the past two decades, compounding its earnings at an extraordinary pace.

Just last month, this ASX 200 stock reported 2% revenue growth for its first-half of the 2025 financial year to $873 million. Net profits were up an even better 26% to $314 million, allowing the company to hike its interim dividend by 26% as well.

I'd be happy to pay a premium for REA shares, considering this company's obvious quality. However, the current share price, at over 53 times earnings, is just a little too expensive for me, even after a recent dip.

If REA came further off the boil and got down to even a 40 earnings multiple, I would probably have to pick up some shares.

TechnologyOne Ltd (ASX: TNE)

Next up, we have ASX 200 tech stock TechnologyOne. This company is a leader in the ASX tech space, providing enterprise software for businesses and governments.

Like REA, TechnologyOne has been growing at a healthy clip for decades. Last November, the company reported its full-year earnings, which revealed that its revenues had grown by a robust 17% over the 2024 financial year.

Profits before tax rose by an even greater 18% to $152.9 million. That enabled TechnologyOne to boost its final dividend by a whopping 46%.

So you can see why I'd love to get a slice of that action. Again though, this is not a cheap ASX 200 stock right now.

At current pricing, TechnologyOne shares are trading on an earnings multiple of over 80. This would need to come down substantially for me to consider a buy. Let's hope it does.