I'm going to Italy in September on a 9 month contract :-) I met my family through Au Pair World too, like most people on here and I have to admit half the reason I picked my family was that yes they seem really lovely and down to earth (and i've spoken to their current au pair who reiterated that) but also that their salary is really good in comparison to what others offered me (€100/week for 20-25hours, my own apartment on the floor above theirs, an italian phone and contract paid for, language lessons paid for and an annual bus pass) but i am sure i'm pretty alone in how lucky i am with a contract like this...
i think it also depends on the cost of living... like if you live in a main city, it will be more expensive in say Madrid or Rome, in comparison to the lesser known places, so you might find families are willing to pay more. :-)