We didn't find such a place in Quebec city, but in Montreal, try:
Au Petit Extra, 1690 rue Ontario Est, Montréal, Québec H2L 1S7, (514) 527-5552. Dinner will cost around C$20-25 (face it: you won't get a decent dinner in downtown Montreal for much less than that).
Restaurant Europea, 1227 de la Montagne, Montréal, Québec H3G 1Z2, (514) 398-9229. Their 9-course dinner costs around C$70, but you can get a 5-course lunch for less than C$25.
We still don't know why hotels and motels in eastern Canada are about twice as expensive as those in the US (US$80 or more for Travelodge-level quality, which isn't saying much). We never noticed that in British Columbia.