"I have a bunch of people in different cities that do this, because I want them to know every one of my hairs," O'Leary says. "I don't have that many, so I want them to have a personal relationship with every hair."

"A guy like me has to think about haircuts all the time. Why? Because I don't want to look like Bozo the Clown after two weeks, with the sides growing out," O'Leary tells CNBC Make It , motioning to imitate poofy side hair.

O'Leary gets an $80 haircut every 10 days — which means he's spending $2,920 in a year.

Kevin O'Leary, an entrepreneur and investor on ABC's "Shark Tank," hates wasting money . But there are a few things for which he is willing to open up his wallet .

For O'Leary, those haircuts aren't wasted money — they're an investment in looking professional.

"I invest in looking great all the time, and the way I do it is [paying for] great clothing, great shoes and a haircut every 10 days," he explains.

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According to 2016 data from Square, the average price of a man's haircut was $34 nationwide ($45 for women), so O'Leary is certainly paying a premium. But, experts agree that investing in your personal appearance can be beneficial professionally.

Research from Princeton University reveals people make judgments of others within one tenth of a second, analyzing things like "attractiveness, likeability [and] trustworthiness."

And in a job interview, where first impressions are key, that snap judgement can impact your success, O'Leary's fellow "Shark Tank" star Daymond John tells CNBC Make It.

"Remember, people employ you because they want to be around people like them," John explains. "If you're somebody that is a team player, and you're dressed appropriately, and you're always welcoming to people, and they want to be around you ... then you'll hopefully be able to grow in the company."

John's advice: manicure your nails, shine your shoes, invest in quality clothing pieces that you can mix and match, and make sure you smell good.

For O'Leary, the money spent on haircuts is well worth it.

"People say to me, 'Why don't you cut all your hair off and just be totally bald?'" O'Leary says. "I don't like that look. I like this look. I think I look terrific."

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