Philpott may not be a product of the welfare system but he has certainly used it to further his own ends.
IMHO I really do think that he would not have had 17 children had he had to seriously financially provide for all of them - he just wouldn't!
This 'unemployed baker' with his anti-social, violent, domineering, and self-centred personality would no doubt have made his mark in other ways, but six innocent children might have been spared a dreadful death.
And was there not another similar man recently done for murder who also had 17 children, by a dozen or so women? He was I think only in his 20s/30s. There is no way he, or the girls queuing up to have his children, would have been so keen if they had to support them.
For me, the main issue is not the cost to the state, although it must be considerable, I'm more concerned about the lives most of these children live.