soggy14 - Despite DP only earning £16K pa and me out of work due to disability (though not getting any disability benefits, long story), we are STILL better off by about £40 a month after all our additional costs with DP in work than with him out of work. That is with the aid of Tax credits though, and if DP earnt any less, then we wouldn't be any better off with him in work. This is where I think you have a few misconceptions, as on any wage above £15.5K pa, you will be better off with at least one person working.
It's only if no-one in your household can earn more than that that you would be better off out of work. And TBH, if your educational qualifications and work experience are that low, you have much bigger problems socially than being on JSA/IS and 'living the life of Riley'.
If the only job you can hope for leaves you with not enough money to cover your 'basic' living expenses (which is all JSA/IS covers), then why would you PUT yourself in the situation of not being able to afford to feed your family? It's NOT about benefit rates, it's about wages being paid.
curlymama - I fully understand that smaller businesses would be totally unable to stay financially viable if minimum wage was lifted to a liveable level, as you say, your workplace just couldn't pay you any more. BUT that doesn't change the fact that minimum wage is not enough to cover the costs of living, and if the employers are unable to cover those costs, then the Government is doing that for them (thus sibsidising businesses) by paying Tax Credits to the lowest paid workers.
Tax Credits were originally established because the (then Labour) Government realised that there was a big discrepancy between the amount of money a family needed to survive, and the amount of wages that businesses were willing or able to pay, and something HAD to be done to bridge that gap.