Doha is cheaper than dubai in all aspects is true BUT the salaries in Dubai are comparatively more than in Doha.

Regarding the rents the problem is that the Government in Qatar just developed Doha. They forgot cities outside doha and everyone wants to live in Doha so the rents are very high in Doha and there is no other place to live outside doha as most of them are very much under development.

Dubai is much more planned and organized whereas in Qatar urban planning and development is relatively new. For example whenever they block access to a road for maintenance in Qatar they forget to provide an alternative.