I live in Scotland near Edinburgh, my first dev job I was earning £13k. It isn't super easy to break into development in the UK but within a year that had about doubled and that and learnt enough to be able to jump ship, which I did.

Now years later, I've happily earning more than the London average by contracting. I ate shit early on because I wanted to get somewhere in an economic time where the young are being screwed. I think it was probably worth it, but only until your experience and talent matures a bit.

I made very nearly that as a fresh graduate with an unremarkable degree and no relevant experience. Out in the sticks with more reasonable living expenses. Thirteen years ago, and I'd come close on several better paying positions. (Tip BTW, £400/mo after rent won't be enough for independent living.)

You're letting loyalty cloud your judgement; you can do better for yourself. Counting pennies isn't fun and you don't need to.