Staggering cost of the engagement ring Travis Barker gave Kourtney Kardashian revealed

When Travis Barker proposed to Kourtney Kardashian at the weekend it was not exactly a low-key event. Photos of the proposal show the couple surrounded by an extravagant display of roses and, while it looks like an intimate moment, reports claim that many friends and family were in attendance.

One of those in attendance was Kourtney's younger sister, Kim Kardashian, who later shared a photo of the ring Travis gave Kourtney, to her own Instagram. The ring is strikingly large, which has led many to speculate as to its cost.

Experts in the area of all things diamonds and sparkly gems have weighed in, giving their estimation of the value of the ring, and it is huge.

Mike Fried, CEO of The Diamond Pro, told Page Six Style, that his valuation of the sparkler put the price of the ring at a whopping $1.86 million (US$1.34m) ."It appears Travis has bought into the Kardashian family philosophy of going big and going flashy with the enormous oval-cut diamond engagement ring he gave to Kourtney," states Fried. "It looks to be larger than 15 carats in a pavé or hidden halo setting," he continued.

When Travis Barker proposed to Kourtney Kardashian on the weekend he kept up the family tradition of large and lavish engagement rings. Photo / Instagram Stories

Other opinions estimate the value to be substantially lower than Fried's US$1.34m, but still in the eye-stinging range for most mere mortals.

Olivia Landau, GIA-certified gemologist and founder of The Clear Cut, told Fox News that she estimates the size of Kourtney's sparkler to be "around 8 to 10 carats." According to Landau, it's cost would fall well under the US$1m mark.

"It is set in a skinny platinum solitaire style with a pavé diamond band. Depending on actual size and quality it could range between US$470,000 and US$870,000 ($655,436 to $1.2m)," Landau estimated.

Lavishly large diamond engagement rings are par for the course for the Kardashian women. Kourtney's younger sister Kim Kardashian received an estimated $6.97m (US$5m) engagement ring from Kanye West when they got engaged in 2013. More recently, when Khloe Kardashian became engaged to Tristan Thompson earlier this year, the sparkler spotted on her finger was estimated to be worth $4.6m (US$3.3m). Sadly it seems Khloe's relationship with Thompson has since come to an end.

Kim Kardashian's engagement ring from Kanye West (left) was estimated at US$5 million, while earlier this year Khloe sported a US$3.3m ring (right). Photos / Instagram

Travis and Kourtney's engagement took many by surprise as the couple had only been dating since November last year.

Blink-182 drummer Barker was previously married to former pageant queen Shanna Moakler and they share two children. In an Instagram Story posted on Monday Moakler led many to believe that she was not happy about the engagement, when she shared the words: "Temporarily Closed for Spiritual Maintenance."

In addition, Kourtney's ex, Scott Disick, with whom she shares three children, is said to be struggling with the engagement news.

A source close to Disick told Page Six that: "Scott is going crazy."

"He's going to go off the deep end. It's really bad. It's about to get dark," the source added.

Disick and Kardashian officially called their romantic relationship off in 2015 after nearly a decade of dating on and off. They were never married, this will be the first marriage for Kourtney.