The value of Hulk Hogan-related items is skyrocketing after the wrestling legend’s tragic death … with one piece of the Hulkster’s history expected to go for nearly double the original price tag.

A pair of 1999 nWo boots worn and signed by Hogan were already slated to hit the auction block on August 24 (prior to Thursday’s news) … and initially, experts predicted they would find a new owner for around $40k.

We’re told the wrestling legend wore the boots in five matches, including the SuperBrawl IX, where he defended his WCW World Heavyweight Championship against Ric Flair.

Heritage Auctions got the boots from the consignor’s father, who had a long relationship with Hogan and “worked on his sound system for years.”

“One day he brought his kids over to meet the Hulkster, and Hogan invited them to his gym and gifted them these very nWo ring-worn boots,” HA said in a statement. “Both sons received a boot from Hogan, and they were reunited for the first time when they were recently consigned.”

HA also verified the boots via Sports Investors Authentication, which found “definitive matches” to the five bouts Hogan competed in.

The boots are now estimated to fetch between $60k and $75k following his death … with HA pointing out not a lot of Hulk-worn gear is available to the public.

Hogan’s pro debut was in 1977, and he retired in 2012 as one of the greatest wrestlers of all time. The loss was felt by countless peers and fans … including Flair, who joined Harvey Levin on “TMZ Live” to mourn his friend’s passing.