Australian furniture in the post-war modernist style has been booming at auction over the past 10 to 15 years, so it was no surprise to see one of Grant Featherston’s orange talking chairs selling for almost $15,000 last month.

The Expo 67 Mark II  chair is one of a limited commercial production by Aristoc, based on the ones made  for the Australian Pavilion at Expo 1967 in Montreal. Their feature is the pair of speakers incorporated into the headrest. Groovy, as Austin Powers would say.

The chair – part of a private collection of Featherston furniture - made $14,640 (including buers’ premium) at  Leonard Joel’s Modern Design Auction on June 26. If that price sounds impressive, it is, but prices for Expo chairs have been impressive since 2009 when Shapiro Auctions in Sydney sold one for $12,480 IBP. In 2010, Leonard Joel sold a rare Featherston SR161 Settee for $8,400. ‘‘In my opinion, prices for Featherston have now plateaued,’’ says Andrew Shapiro.

He has some of those listed at his next 20/21 C Art and Design sale in Sydney on July 30 (starting 6pm) but appears to be more excited by the unique collection of modernist furniture by Melbourne designer O. Noel Coulson. These were commissioned in 1958 especially for the Toorak home of fashionista Mary Lipshut, who died earlier this year. The furniture was custom-made by S. Andrewartha of Richmond, Melbourne.

Oswald Noel Coulson was born in Geelong in 1905 and worked as an architect, interior designer and landscape designer. He did the gardens for the 1956 Olympic Games village in the Melbourne suburb of Heidelberg but the core of his business were interiors for wealthy business people in Toorak.

‘‘I think he is fascinating as he was the only Australian version of world-renowned designer T.H. Robsjohn-Gibbings who did all the furniture for Conrad Hilton in the '40s, '50s and '60s,’’ says Shapiro. It’s a style he describes as ‘Hollywood neo-classicism’, inspired by ancient Greek design but with a space-age Jetsons feel.

Pieces by Coulson rarely appear at auction. In 2009, Shapiro sold one of his table lamps for over $3,000 and a limed oak pedestal table for $5,000.

Shapiro has placed conservative estimates on the Lipshut furniture but is expecting some very competitive bidding. Perhaps the signature piece is the eccentric telephone table and chair, made of limed oak with brass sabot feet. Estimates are $1,000 to $1,500.

Among the most expensive is a streamlined low cabinet for $2,000 to $3,000.

Potential bargains include an upholstered armchair (estimates $400 to $600), a pair of table lamps on marble bases ($400 to $600) and a coffee table ($600 to $900). See catalogue on the Shapiro website. Demand for this style is high among an urban market of 30 to 60 year olds living in contemporary glass-walled apartments where this 50-year-old furniture seems to belong.

Australia’s top exponents from the post-war period include Schulim Krimper, Dario Zoureff, Paul Kafka and Douglas Snelling. Pieces by cabinet maker Fred Ward are also highly-desirable. Leonard Joel in Melbourne and Shapiro in Sydney are the main sources for this style at auction.

Shapiro notes that modernist furniture now fetches around three times the equivalents from the 18th and 19th centuries. The reverse ratio applied thirty or forty years ago when chairs by Grant Featherston could be freely found on nature strips on chuck out night. Krimper is perhaps the strongest performer at auction.

The current record for his work was set in November 2009 when Shapiro sold a sideboard made of blackbean for $36,000 IBP to the Queensland Art Gallery. This piece came from the home of Mr and Mrs George Shaw of Toorak, who had bought it back in 1952.

Last year Shapiro offered a suite of Krimper furniture which had been commissioned in 1962 by one Melbourne family for their house designed by architect Robin Boyd.

As with fine art, such provenance adds greatly to its value.