so you are free to reside wherever you want.
If the budget, as well is not an issue, so you can go to JoPo's suggestion, but I doubt you will find something that CHEAP!!!!
However, I cannot see why the lagoon is that overestimated.
I'd say AlFerdan or Beverly Hills AlRayan complexes are the best choice Doha.

In case the children will be enrolled in school, forget about. Just take the closest compound to the school.