i have read some questions that ask "how much is the hardware etc to mine, and how long for it to pay for itself" which i think is a reasonable question, many answers explain how much it costs to buy a mining computer etc! but i cant see where anyone says "mine cost £xxxx and it generates £yyyyyyyy in real pounds cash! what ishard about the question? so lets say i buy equipment for £1k what return can i expect versus running costs?
You can't sensibly evaluate the costs and benefits of mining that way. For example, consider this horrible (for you) idea:
1) Buy Bitcoins.
2) Give half those Bitcoins to me.
3) Wait two years.
4) Sell those Bitcoins.
Is that a good idea for you to do or a bad idea? Well, if you look at how that idea would have worked over the past two years, computing your costs in pounds and your return in pounds, that seems like a great idea. But it's obviously a really bad idea.
So don't ever evaluate the profitability of Bitcoin investments in fiat currencies. It makes even really bad ideas look good.