My advice to you is do not accept the offer, its too small,the way of living her in Qatar is so high,maybe you will spend in your food in one month-300QR(this is reaaly tipid budget)then you will rent a house if you dont have a free housing accomodation--the least room price here that you can get is 1000-1500, that is over to your salary, so this is clear that you will have a negative salary.
So my advice is you is.. do not accept,or demand for a free house and transportation allowance, so you will just spend for your food.
If the salary offered is only this amount, its better to work there in the Philippines.Malapit ka pa sa pamilya mo.