Sephius
Hi
For 3 people ( I am assuming for you and your parents)you can live comfortably with u$1500/month , give or take a few hundred.
Punta del Este is probably the best place to live in all of South America but is expensive. You are better off living in Montevideo or La costa de Oro,( La costa de Oro is about 45 minutes from Montevideo) buying a nice house in the neighborhoods of Pocitos or Prado. As far as safety Uruguay is by far the safest when compared to Panama or Ecuador, it has better infrastructure, more educated population, better schools etc, Being from Portugal yourself you will find a lot of similarities with your country, in the architecture of its buildings and its people since Portugal played a very important rol in Uruguay's history and development. its proximity with Brasil makes it possible for people to understand portugese. Also, if you are of school age, you can go to the university for free, never have to pay a single cent, unless you choose a private one.
Anyhow, should you have anymore questions i'll be happy to answer them. I am a native uruguayan living in USA for many years.