 On leaving this service he became an auctioneer and stock salesman and a member of the real estate firm of Coles and Goodchild, with which James White was later associated.The business prospered so much that Coles was able to practically retire from it before he was 40.He was returned to the South Australian House of Assembly as member for Light in 1875, but did not stand at the 1878 election as he found that the strain of carrying on both business and parliamentary duties was too great.