I suspect that RISM might already have made his decision by now but my comment would be that Education should be another consideration, not only the cost but also the availability.

Dubai schooling is very over-subscribed and the best schools have long waiting lists. Unless the company sponsoring you has significant pull with the school, your kids might not get in to the schooling of your choice, or may have to join very large classrooms.

The other family consideration is whether the Spouse will want to work. Both Singapore and Dubai local companies, or international companies hiring at admin/junior level prefer a 2nd language as well as English (mandarin or arabic).