i think ultimately, money can't be the sole deciding factor on whether you have another child. it can be A factor, but not THE factor. most people learn to live within their means. it might be different means to what you have now, but it's what you have then. i've been the child of parents that were on reasonable money, but dad got hurt, took a redundancy package when interest rates were excessively high, paid out the house, and lived on income support for over 13 years. it's NOT ideal - but, as a family, our priorities changed, we lived a different lifestyle - but we still survived!

given your DH's varied background, there is no reason to think he'd be long term unemployed. there will ALWAYS be work for skilled labourers - academics might struggle a bit, but labourers will always be needed. the pay might not be as good, but it's still a job...