When I was there I paid $250us for a month in a descent house then I went to live in a friend house and took the bus everyday, if I were to say rent in a descent place could be in the range of $150us to $1500us depend on your tast, for me I didn't care where I live as long as it safe and clean. Food isn't too bad in terms of price, I paid $2 to $6us a day for a good lunch but again I didn't mind the comedor(street food) and I never went for fast junk food. And their food is delicious and most importantly the people are nice. You may get internet at home but if not use your phone wi-fi its in the range of $10 to $20 a week you will need an ES sim card but signup but pay as you go. El Salvador is safer than usa and even canada in my opinion. Make friends watch where you go ofcourse, don't act like you have money but don't be too cheap either. Most treets are safe. If you compare the cost of living between the west and ES you will see what I mean about safer. Even the homeless there are safer.