The Kardashians are known for living in the lap of luxury, which includes going all-out for birthdays, especially for the younger generation. But some of the gifts they give are priceless.

Kim Kardashian recently shared the sentimental gift she give to her four children every year on their birthdays, which she believes they’ll appreciate even more as they get older.

“Every year I write each one of my kids about a four or five-page letter on their birthday, about what the year was like, who their friends are, silly words they’re saying, their favorite foods, all the silly things they do and a little journey of what the year is like,” Kim shared during an appearance on the podcast On Purpose with Jay Shetty.

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“And it’s so fun to see from the first year now, one of ‘em is almost 10 years old. And I know that they’ll appreciate this,” the SKIMS founder added. “I know that they’ll appreciate everything, even if they might have thought I was being a little harsh on them. I know that they’ll get it because I got it with my mom. I know they’ll get it with me.”

But Kim’s sentimental gift doesn’t mean she doesn’t also spoil her kids on their special days. For example, just earlier this month, the reality star reportedly spent a small fortune on her son Psalm’s 4^th birthday.

Guests were treated to a firefighter-themed party, which included elaborate decorations, a huge spread of food and treats, and tons of party favors for the young guests.

Kim reportedly enlisted the help of her close friend and party planner Natalie Halcro to transform her Calabasas home into a life-sized firefighter station.

One report suggests that the party planner’s fee could’ve been at least $50,000. Kim likely spent $10,000 on party favors, $10,000 on a videographer, and $45,000 for staff and security to work the event, meaning it easily cost her six figures to throw the extravaganza.

But Kim isn’t the only one of her sisters to go big for her kids’ birthdays. When Kylie Jenner’s daughter Stormi turned 2-years-old, the makeup mogul allegedly spent $100,000 on a Stormiworld party to celebrate.

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Sources: PEOPLE, Capital Xtra,