Across two floors in a building in Waterloo, 10,000 hire costumes that include original Priscilla headdresses, Jane Austen gowns, raunchy burlesque skirts and even the Sunrise Cash Cow are up for sale.

The Costume Shop has served Sydney for 30 years, dressing thousands for Oktoberfest, Christmas, Mardi Gras and Halloween.

But eager for a break, the shop's owners Kitty Hoh and Wing Chung have decided to sell everything and close its doors.

"It's not that we are going because of lack of business. We are going because we couldn't find someone to take the baton on," Ms Hoh said.

Kitty Hoh says the closure will be sad but she's ready for a break. ( ABC Sydney: Harriet Tatham )

She said it would be a huge loss to the city's theatrical and party scene.

"This is a very special type of business.

"When you make a costume, it takes a lot of manpower, lots of hours — there's a lot of memory associated with the costume.

"We have 10,000, easy, because you're talking about a 30-year collection.

"Nowhere else can you see so many costumes in one place with all different periods, all different timeframes, people with different occupations, different countries, different animals and mascots — you name it, we've got it."

Customers say the closure will be a big loss to the theatrical scene in Sydney. ( ABC Sydney: Harriet Tatham )

Most of the costume racks are filled with designs envisioned and fashioned by the store's in-house designers, unlike other costume shops that ship in clothing from factories en masse.

"We have a team of creative stylists who use the pool of costumes that we've collected over 30 years from Opera Australia or from other Australian theatre [groups]," Ms Hoh said.

The average make-time is between three and four months.

The collection includes at least 40 bridal hats from the 1960s. ( ABC Sydney: Harriet Tatham )

'Pieces of Australian history'

While many of the designs are interpretations of well-known costumes from TV shows like Game Of Thrones, some are originals.

"We have an original headdress from Priscilla up for sale.

"They're a piece of Australian history."

The original Priscilla headdresses from the musical are up for sale. ( ABC Sydney: Harriet Tatham )

Ms Hoh said the collection once included a tuxedo used by tenor Luciano Pavarotti.

"When Pavarotti, the opera singer, was in Sydney we got his tuxedo," she said.

"Like all famous people, they have their name written on their tuxedo inside.

"We trust people to have a good time with the costume, but someone actually decided to keep it and we never got it back.

"That's the thing with a hire business — we want to share the experience but unfortunately sometimes it goes missing in action."

Costumer Ben says he's hired costumes for parties, Mardi Gras and Oktoberfest and is sad to see the shop go. ( ABC Sydney: Harriet Tatham )

The collection includes period costumes, something performers Eduardo and LaTara Kite are making the most of. ( ABC Sydney: Harriet Tatham )

Ms Hoh said while the looming prospect of a holiday was exciting, the shop's closure in November would be sad.

"I think Sydney will miss us when we go.

"We are one of the big icons in the costume hire business, and with us going by the end of November it will be cheerio and ciao, and you won't see anything like this ever again."