Working out of the kitchen of their small restaurant in Ontario in the 1970s, Irene Demas and her husband Tony soon learned the value of trading their dishes for the talents of local bakers, craftspeople and artisans.

“Everyone supported everyone back then,” said Irene, at the time a bright-eyed chef in her 20s. In exchange for daily fresh flowers, for example, the couple would take soup and a sandwich to the florist next door.

And for an English painter with a predictable palate, the couple struck a deal: they would get a selection of paintings from him and his friends in exchange for grilled cheese sandwiches.

By chance, that deal unwittingly netted them a painting by the acclaimed Canadian folk artist Maud Lewis – a work that nearly five decades later is expected to net more than US $27,000 when it goes to auction this month.