A very good friend's older teenage (university age) son may lodge with us for up at a year. He'll have a double room, and we'll provide the majority of food (breakfast, lunch, dinners). He'll go home on the odd weekend, and holidays etc. We are not doing it to make money but equally can't afford to be out of pocket. What do you think would be a fair amount to suggest we charge per week? We've never had a lodger before and I have literally no clue!