One tycoon is selling two of America’s priciest mansions

[Editor's note: This is a guest post from Laura Vecsey at Zillow Blog. Also, the post has been updated to correct two errors: It is the Bradbury Estate, not the Bradford Estate, and the shooting ranges are 25 yards, not 25 feet.]

Call it a $78 million change of heart. Times two.

Commercial real estate tycoon Don Abbey has listed his pair of custom-built mansions -- one in California and one in Montana -- for $78.8 million and $78 million, respectively. That firmly gives him two of the top five most expensive listings in the United States -- for now, anyway.

Even with similarly whopping price tags on both unique properties -- one in an exclusive Los Angeles enclave and the other on a private island Montana's famous Flathead Lake -- the homes are attracting interest. (Click on the photos above and below to go to a slideshow of each estate. And you can see even more photos of the two $78 million estates on Zillow Blog.)

According to Bob Hurwitz, listing broker for Abbey's twin gems, the home's list prices intentionally included the numeral 8 because it represents good luck for a key group of potential buyers: wealthy Chinese investors who are looking for ready-made luxury.

And while Abbey, founder of The Abbey Group, did not build either of his homes with resale in mind, the incredible detail and luxury poured into these homes makes them one-of-a-kind prize possessions.

Fireplace rings in for a $1 million

The Bradbury Estate is Abbey's 8-acre masterpiece in Bradbury, CA. The 7-bedroom, 10-bathroom mansion sprawls over 30,000 square feet and is covered in French limestone, Venetian plaster, leather and oak paneling. The Italian marble fireplace alone costs $1 million.

When Abbey wasn't swimming in the Celtic-cross-shaped infinity pool at this exclusive spread east of Pasadena, he took a private jet over to his "country" place -- a private compound on his own island on Montana's pristine Flathead Lake.

[Related: The jaw-dropping Chateau d'Or is marked down almost 50% -- to a mere $25 million.]

Known as Shelter Island Estate, the 24-acre compound resulted from 10 years of planning and designing and meticulous construction that could never be duplicated.

Hurwitz, who is regularly featured on "Extra," "NBC Open House," "Mansions and Millionaires" and HGTV's "Million-Dollar Room," and who is a top real estate agent in Los Angeles with worldwide listings, said he has rarely encountered an owner who put more meticulous care into building a luxury home.

$3,000-per-square-foot price tag

Not only did Abbey buy the rare Flathead Lake Island, Abbey also had to buy mainland property to use as a staging area to have the materials and equipment shipped over to the island for construction of the fortress. At 24,000 square feet, it is the largest private home for sale in Montana.

"A lot of things have gone into building these houses that make it interesting to try and price them because there is nothing else like it," Hurwitz said, adding that the $3,000-per-square-foot building price does not really cover actual costs for building these homes.

"He did not build these homes to sell them. They're insane, unbelievable in terms of what he put into them," he said.

[Related: The Dakota, New York's most exclusive building.]

Hurwitz said despite the ostentatious homes he built, Abbey sees himself as an outdoorsman who wanted to incorporate his love of fishing and hunting and sports into each of his two unique properties.

The Shelter Island home has a boathouse mechanism that allows a water craft to be brought from the lake into moorage under the home without anyone ever having to walk on a dock.

The Bradbury property comes with a million-gallon trout pond where the water temperature is controlled.

"It's larger than the Aquarium of the Pacific (in Long Beach, CA) and it cost $8 million to build," Hurwitz said.

In addition to stunning materials and attention to detail, one other feature shared by both estates: an EPA-certified, 25-yard shooting range.

"Lucy Liu used the shooting range to practice for her role in 'Southland,' " Hurwitz said.

See even more photos of the two $78M estates on Zillow Blog.