Colin Gleadell frames the Grovesnor Prints sale at Bonhams with this history of their prices:

Flight’s Brooklands, a 1927 image of racing cars, sold at Christie’s in 1999 for £23,000, a record for a Grosvenor School print. But his best work has been rare at auction, where the record £26,400 was set at Bonhams in 2009 for Speed, a view of London buses hurtling down Regent Street in 1922. Another print of Speed is at Bonhams with a £20,000 to £30,000 estimate that could beat the record.

One of Cyril Power’s more sought-after images, The Eight, is a view of oarsmen powering their way under Hammersmith Bridge, which Redfern sold for about £2,000 in the 1980s. Last year, it commanded a record £57,600 at Bonhams, while another print of it (left) will be at the fair with Osborne Samuel for slightly more.

Lil Tschudi is looking comparatively more affordable with prices yet to reach £17,000, while Ethel Spowers took the market by storm with an unexpected £52,000 print at Christie’s last year.

But it has been Sybil Andrews who has led the Grosvenor School field. In 2006, Ryan sold a print of her Speedway to the Museum of Modern Art in New York for $50,000, and in 2008 a Speedway print sold at auction in Canada for £66,300.

Speedway made £82,850 in today’s sale.

London Original Print Fair: Prints that move like lightening (Telegraph)