It's a jungle out there! Better book quickly as anything other than the advance purchase rates are truly eye-watering. Don't know if helps your particular issues but we've started using Miss Maud's in the city, or the (refurbished) Metro on Canning H/way as reasonably priced options for work visitors. Ask for a city view in the latter or you'll be ON Canning H/way. Metro is marginally more convenient for YPJT. A few nice places in Fremantle, too, but our visitors have found them a bit hit and miss, quality wise. Good luck, and prepare yourself for the $4.50 espresso
But we love it here, really.