Re: It's like the sixth form common room
I wasn't going to get sucked into this but...
My sister, a well educated and experienced person, has been struggling for a long time to find a permanent, full time job. She's managed a few temping roles, and some part time work, but has lost out to people who have been in the exact industry sector of the job, or have experience of specialist (or often not so specialist) fields. She, like I have in the past, has been turned down as "over qualified". Plus not everyone is part of a couple. So your assumption that anyone who wants can work a 40 hour week, then double that income up , is completely unrealistic.
An hour a week overtime adding up to £5k a year? If both do that, at minimum wage you're looking at well under £1k a year.
Not everyone can move at will either. Assuming there ARE 2 people in the equation, if you move to get one of them a job then the other one is a bit stuck until they can find something. And what if they have children, to take out of school etc? Please don't try the old "they shouldn't have kids if they can't afford them" thing, maybe they could until one (or both) partners were made redundant - there's a lot of it about.
Cost of living is an interesting one. If you do manage to scrape together the deposit and buy, you need to also find lighting, heating, council tax, buildings and contents insurance, phone, internet access etc. Then you have travel, either by car or public transport - where I live, a return ticket for an under 3 mile journey is well over £5 by bus, so would be well over £100 a month just for that. Your scenario of commuting from a cheaper area really does show a lack of thought - I live JUST outside the M25 and commuting to London would be £4-5k a year for me - once I'd got to the station either by bus or paid £6 a day parking.
Add in unessential things like food, drinks, clothing (it does eventually wear out you know), toilet roll, shower gel & shampoo etc, cleaning products, any medications (no free prescriptions if you work, no matter how low paid).
Do come back with a detailed list of the costs of all these things, and show us just how much is left to pay that mortgage off (if they can get one at all)