It is a good offer. Check whether your salary will be taxed though, and if yes - ask your agent (I presume you have one) or your employer how much of the tax they are willing to shoulder. Usually it would be a certain percentage. QR 2500 a day is fairly decent for Doha, so unless it's way lower than your usual package I think you should accept. Life here is not all that expensive, and if the accommodation is provided or you have a generous accommodation allowance you should be OK.