I think that Al Sudan is quite a posh but inexpensive area in comparison to the above. its other advantages are that most schools are located there, and don't forget that there are always new residential areas cropping up in Qatar.

Al Saad is supposed to be quite cheap to rent, and lost of shopping places scattered around it.

best thing is to hook up with estate agents and ask them to take you on viewings all around....homezto rent is quite goo. get in touch with nirvan thhere-he is quite well informed and helpful

best of luck