Housing allowance isn't enough, consider it housing assistance.
Everyone comes to this region for different reasons. Many sadly due to the failure of the company they work for, others for career advancement; moving into the airlines. Not many come here to "make money".
Firstly to be happy here your wife and kids need to speak good English. Due to historical links to the UK and more recently commercial and military links to the USA, English can be used for all interactions with government and for the purpose of this thread, securing a property lease.
As for prices, it is possible to secure accommodation for less than the allowance and many pilots choose to share at AKG, Holiday Villas or Ezdan Towers. This is normally done before families arrive, most guys get through training first then bring the Mrs and kids down. This gives them time and extra cash to set things up.
The down side in having to source accommodation is that you only accrue housing allowance once you move out of the company accommodation(4-6 weeks). However when you sign a lease you need one month up front, plus a half month for the agent. If you proceed with an agent (they normally know every detail about QR ) you give 1 month cash + 11 months pre-dated cheques. Also one undated cheque for an additional month. This is the security deposit. Some guys like to do it without an agent, then normally you need 1-3 months cash up front. (system revolves around agents, same with most transactions down here and the agents are trust worthy, working on referral)
As for the housing available, there is something for everyone and many new developments coming on-line in the next 6 months. You pay for The Pearl, but it is the most similar to Western standards and you do feel away from the City. Prices 10000 to 25000. Pricing normally works a) on size b)no of bedrooms c) pool-gym-creche facilities, amount of sun at the pool due to orientation of building! is there a balcony, are you overlooked.
If you have a big family then there are many nice villas in west bay lagoon area.
If you want to be near work there are also some nice compounds outside D-ringroad on the way to Aspire.
Roads are a nightmare and things will get worse, before it gets better due to large road building and improvement plan. If you have kids then worth bearing in mind, you would need accommodation near schools, however you will pay more.
Good book to get hold of is Qatar Complete Residents' Guide
ISBN 978-9948-03-317-2
lots of good info regarding areas of the city under "Residents" section