Quote From Fled:
Not sure I am convinced about the "If it's free, its always better" argument.
That's not really the argument I was putting forwards.
Obviously any funded offer still needs to be critically evaluated. But I think the risks associated with an unfunded PhD are not (for most people) worth it. As Ian says, the direct cost of doing a full time unfunded PhD in the UK is around £50,000 in fees and living expenses. But there are also indirect/opportunity costs. By doing the PhD full time, you prevent yourself from obtaining a paid full time job, which would probably pay you at least £15,000 a year. So if you factor in that too, you're looking at an 'investment' of around £100,000 into a qualification that has a low chance of guaranteeing the desired career path subsequently. For most people that would not be a smart investment.
So, if given an unfunded offer, I would only take it up if I could secure external funds (e.g. from charitable trusts) or do the PhD part time so as to (i) have an income and (ii) get employment history for my CV to fall back on if the academic career doesn't work out.
Good luck with your decision.