Bit different for me as I went to sea just about straight from school, but whan I came home I was charged board and my part of the phone bill. Think it was £70 / month plus phone calls in 1994-97. Went up after I qualified but it was never all that much as my mum was just glad to have me home, aaaahhhhhhh. My dad on the other hand couldn't believe it that she agreed to such a small amount.
To be honest these days I'd look at maybe £150 / 200 a month for fod etc and phone calls on top.