Today his collection stands at home in a sleek 2m x 2m light-up glass display.

“My wife is very supportive,” Tsoi said. “As long as I have enough for the family, she lets me buy what I want.”

Watch: Inside the secret hideout of a superhero fanatic

Tsoi represents a breed of collectors in space-starved Hong Kong who have caught the toy bug. They are willing to splurge on high-end figurines of their beloved comic book and movie characters, cramming their homes or renting mini-storage units for their stash.

The high-end toy market itself is a recent and growing niche in Hong Kong’s toy industry – a sector that harkens back to the 1960s and 70s, when the city enjoyed its heyday as the world’s “toy town”.

Statistics from the Trade Development Council show that domestic toy exports have declined almost 40 per cent from HK$277 million in the whole of 2015 to HK$171 million from January to November last year.

But Yeung Chi-kong, executive adviser of the Toys Manufacturers’ Association of Hong Kong and the Hong Kong Toys Council, said most local toy companies had shifted their factories to the mainland, so the full extent of the business, which is “positive”, was not being reflected.

“Our toy industry is moving towards the application of creativity, innovation and technology to meet market demands,” Yeung said, adding that while high-end collectibles represented a small segment of the industry, their demand was “growing”.

A company that has tapped into the pulse of this trend is Hot Toys, a home-grown brand that has achieved international fame for its uncannily lifelike 1/6-scale replicas of Hollywood actors in superhero roles – from Robert Downey Jr as Iron Man, to Chris Evans’ Captain America and Christian Bale’s Batman.

CEO Howard Chan Ho-bun, a collector himself, has a 3,000 sq ft retail showroom for his business, which also doubles up as a display for some of his private collection.

Called Secret Base, the outlet, true to its namesake, sits on the 20th floor of Sino Centre in Mong Kok. Its location is known to fans mostly through word of mouth and on Facebook, where it has a following of 50,000.

Designed to look like the inside of a space ship out of a Star Trek movie, futuristic doors glide apart at the entrance, welcoming wide-eyed visitors into the man-cave of every collector’s fantasy.

Chan went from a struggling toy maker who cut his teeth in the trade by sleeping in Dongguan factories, to helming a company with Hollywood licences and offices in South Korea and Japan.

A Korean head sculpting design team is behind the signature realism of Hot Toys products. According to Chan, the figurines have to be approved by their real-life counterparts before production begins.

Actor Samuel L. Jackson for example, who plays agent Nick Fury in the Marvel cinematic universe, once posted an Instagram picture of his beaming self with his Hot Toys equivalent.

Being close to the mainland also works in Chan’s favour. He said: “We have a shorter turnaround time in terms of communicating product tweaks to our factory, so we can lower our costs.”

The enthusiasm of collectors is best observed when Hot Toys takes pre-orders for its products. Store manager Gavin Lam Yan-por said before Secret Base opened in 2013, queues would form at Toy Hunters, the official distributor for the brand. The retail shop is located on the second floor of CTMA Centre in Sai Yeung Choi Street, Mong Kok, a block behind Secret Base.

“We had people queuing from Toy Hunters to the street below. It was quite crazy,” Lam, who now also manages Secret Base, said. “The urge to be the first to own a newly released figure is huge.”

But the premium prices collectors are willing to fork out do not stop at high-end action figures.

Over at XM Studios, comic book characters are frozen mid-flight in iconic poses, packaged to feel like museum statue pieces. The Singapore-based brand distributes locally through G-Link (Hong Kong), a local toy importer.

G-Link’s business development manager, Chan York-hall, said: “Although Hong Kong isn’t a big market for statue collectibles yet, it has the potential and we’ve seen a 20 to 30 per cent growth annually over three years.”

He said the collectors’ culture in Hong Kong was largely unaffected by the economic downturn.

“These characters have been around a long time and generations who grew up with them are now working adults with disposable income. They buy because of sentimentality and appreciation for workmanship,” Chan said.

An XM Studios statue can weigh more than 20kg and is delivered to the doorstep of buyers.

While Hong Kong takes after Japanese anime culture, Chan said the market was versatile and his statues of American comic book superheroes, from X-Men to Spider-Man, were gaining traction with collectors.

Prices range from HK$4,000 to more than HK$7,000 a statue, and only 999 pieces of each item are produced. Thereafter, resale prices can hit HK$20,000 for the most coveted product.

“Here, it is more of an issue of space. Some of our clients place their items in rented storage and take them home to admire on a rotational basis,” he said.

Computer programmer Juan Marvin Wirjomartono, an Indonesian working in Hong Kong, is an avid statue collector, and owns some from XM Studios. He also does YouTube reviews of his haul under the channel “Koleksi Saya” in his native language.

He said: “I consider statues as art. People who like reading comics, watching movies or playing video games will understand this.

“These mediums tell stories. But the stories are not physical. Figurines and statues capture them into something we can touch and hold.”

In the same vein, Iron Man fan Mars Tsoi added: “I don’t really care about what others think. Everyone has different hobbies – some people like clothes, but my passion is toys.”

Additional reporting by Sarah Zheng