Yes you are right, housing allowance is not meant to be saved, and neither is perdiem. But, those opting for apartments are able to save quite a bit of it. No crime in that, is there? My point was that if you are here with a family, whether at FD or with someone else, there are other costs that add up, lowering your discretionary income.
As far as coming here, it's a decision left to the individual. My own take is that if you are on an established track elsewhere, it would not be my recommendation.