March 2, 2012— -- Kevin, a cheery, curled-top boy, extends an invitation to his friend by cell phone, "I'd love to have you come over and play."
For most children that play date at Magic Crystal Valley in Maryland would be a dream come true: riding a miniature train, a motorized swing and even a hot-air balloon that sweeps them 30 feet in the air.
But Kevin, and his hundreds of friends from around the country, are Cabbage Patch Kids, and their "parents" are humans who are obsessed with the ugly, but cuddly dolls that hit the market by storm in 1983.
Pat and Joe Prosey own 5,000 and they consider them their own children, even though the 64-year-olds have a real-life grown daughter.
"They are kids. We don't use the word D-O-L-L -- they might hear," said Joe, a former shipyard worker who built this special playground for other enthusiasts.
They are collectors, but say it really isn't about the money, but an obsession with their "babies."
The Proseys and several other Americans with odd passions will be profiled in a TLC series, "My Crazy Obsession!" The television show airs March 7 at 10 p.m. EST.
One woman can't live without objects in pink; another has 2,000 wings to suit her endless personalities. A man named Ron lives in his own oval office and loves all things presidential.
So far, the Proseys have spent $2,000 on their luxury playground. And since 1994, they have operated an "adoption center" for Cabbage Patch originals. "It's a 24-hour job, seven days a week," said Joe Prosey.
"We don't say how much money we have into the collection," said Pat Prosey. "We have over 5,000 dolls [originals now sell for $190 a piece]. We have a 6,000-foot building -- do the math."
The obsession all began with Pat Prosey, a former paint store technician, who had loved baby dolls as a girl. "Mother said one day I would probably collect some type of doll when I was older," she said.
The soft dolls with the wrinkled faces were created by Xavier Roberts, a 21-year-old art student from Georgia, who adopted a German technique for sculpture with his mother's quilting skills, according to his the Cabbage Patch Kids website.
His concept -- adoptable "Little People" -- was developed in 1976. Each doll was different and came with a double-barreled name and a birth certificate.
By the end of 1981, the Cabbage Patch doll had made the cover of Newsweek magazine, and he had sold nearly 3 million kids. By 1990, 65 million had been "adopted," according to his web site.
Pat Prosey got her first Cabbage Patch Meg in 1985 for $50. "She was kind of cute and when I got her got her home, Joe thought I had lost my mind," she said.
But soon, she found a boy, named Kevin, and today he is the spokesman for what has become their personal Cabbage Patch empire.
After Meg and Kevin, came the "preemies" and the ones with freckles. "They went from freckles to teeth to glasses and toothbrushes, and before you know it, our whole house in Baltimore was filled with Cabbage Patch Kids," said Pat Prosey.
5,000 Cabbage Patch Kids and Counting
But when her father offered the couple a farm two hours south in Leonardstown, Md., they jumped at the chance to find room for their growing collection.
She said she thought, "Now, I could actually build a place for my kids," and the amusement park was born.
As for Joe Prosey, he got hooked in the 1980s one day when he was at a waterskiing event and saw a miniature sample of a wet suit hanging on a shop wall. "I thought, that'll fit a Cabbage Patch Kid."
The following weekend, he dressed Kevin the wetsuit and took him waterskiing -- even though has he got strange looks from others.
Soon, Joe Prosey was writing a column in a collectors' newsletter using Kevin's voice. "He was a real kid doing real stuff," he said. "There was such response, a woman phoned us and asked, could I do it again?"
Then, as they met more Cabbage Patch parents, the Proseys sent gifts back and forth -- eventually arranging play dates at their dream playground.
Now the couple displays and sells Cabbage Patch originals. Those from the 70s and 80s can sell for as much as $25,000 to $35,000 a piece.
"Xavier Robert told us, "If you want to prosper at this thing, you have to live the fantasy day in and day out," said Joe Prosey. "The collectors will love you."
Experts say there is a fine line between collecting and hoarding, which a serious psychological disorder.
"With hoarding, we look at three main behaviors: one, acquiring too many possessions; second, having great difficulty discarding something; and three difficulty organizing," said Julie Pike, a clinical psychologist from the Anxiety Disorder Treatment Center in Durham, N.C. "But there is a lot of overlap."
Pike has been featured on TLC's reality show, "Hoarding: Buried Alive," and spoke with ABCNews.com last year.
Collectors are usually well-organized and know exactly where each item is and what they have. They are also proud, not ashamed, of their possessions, she said.
"But if collectors get in a place where they are spending so much money that they can't pay their mortgage, that's a problem," Pike said. "Or if they are spending so much time at it that they can't go to their job or leave their house."
Pat Prosey insists she loves her "fantasy world" and the couple has always had "a roof over our heads, food in our mouths and clothes on our back."
"You can walk out of every day life and there is no harm done, no foul play and have a good time," she said. "People pay $2 million for a painting -- is that crazy? I love my Cabbage Patches like another person loves a Rembrandt or a shiny new car."