Most homebuyers understand the perils of making a financial misstep like buying more houses than they can afford or ending up with a money pit that requires unexpected, big-budget repairs. After all, buying a home is likely the most important financial decision you’ll ever make, and you want to walk away from the process feeling like you made a good deal.

But there’s one less obvious move many homebuyers are tempted to make that real estate agents far and wide would strongly advise against: submitting a lowball offer for the heck of it.

“It’s so common for buyers to see what the sellers paid themselves, realize the sellers didn’t put money into making improvements, and decide that they should pay less,” says Ann Robertson, a licensed real estate agent at Barley and Barley in Washington, DC. “But an increase from what a house cost when it was last purchased and what it is on the market for now is not a 1-to-1 comparison. A lot happened in the market and in the economy that affected prices.”

It’s tempting to try to bargain your way into that gorgeous million-dollar house in that perfect neighborhood you’ve been eyeing. It’s also easy to judge a home as wildly overpriced. But there’s a lot that goes into determining the value of a home.

“Pricing judgments are complex and based on deep and broad price comparisons and data,” Robertson says. “You also have to look at how many days it has been on the market, how hot or cold the market is, and how many offers and viewings it has received.”

That’s not to say that submitting a lowball offer is taboo—you just need to know what you’re doing.

What is a lowball offer?

In real estate, the term “lowball” refers to an offer a buyer makes that is far less than the seller’s asking price. A buyer will submit a lowball offer in certain situations as a means of starting the negotiation process.

If you are determined to make an offer below the listing price, proceed with caution.

“Unless a listing states that the price is non-negotiable, it’s OK to assume it’s negotiable,” says Ying He, a real estate agent with Barb Co. in San Francisco.

But don’t treat buying a home like a flea market haggle.

“If the home has been on the market for at least 10 days and your agent determines it is priced realistically, don’t offer less than 90% of the list price,” says Chuck Vander Stelt, an Indiana-based real estate agent and operating manager of real estate website Quadwalls. “The purpose should be to start a conversation, and anything below the 90% threshold will likely result in a simple rejection.”

When to throw a lowball

A poorly planned lowball can seem like a low blow to sellers. But if done correctly, it can be a win for everyone. If a home has been stagnating on the market for longer than average, or the sellers are motivated to unload it, all signs point to a thoughtful and well-researched lowball.

“If research shows that the seller is motivated and they have no other options, then lowballing is smart,” says Ran Biderman, a strategic coaching adviser at Real Estate Bees in New York. “Looking for off-market deals where an estate is in pre-foreclosure or the couple is in an ugly divorce can lead to deals. Sale-by-owner homes often turn up sellers who are willing to negotiate.”

How to recover from a rejected bid

If your offer has been spurned but your heart is set on the house, don’t give up.

“As long as there was a strategy going in and your agent made an appropriate offer, it can be recoverable,” says Steve Halpern, a real estate broker with Compass in New York City. “Resubmit with a higher offer. The seller is not going to be offended, and it won’t hurt.”

Speak to your real estate agent to determine a path forward.

“Buyers, especially first-timers, really need to lean on their agents when it comes to making offers,” says Halpern. “Real estate agents know how to run appropriate comparisons between homes in the same ZIP code and establish the proper value of the home.”