We paid £30K for the two acres (that we've split into two paddocks) that we own. It's not adjoining our house but it is adjoining our neighbours and we can see most of the top paddock from our house. The sheep can hear us when we are outside and shout at us.
The land we bought was an option when we bought the house but there were a whole load of solicitors involved, due to the way it had been done, and so cost us another £5K on top of that. Very expensive, considering it was just arable land (and fairly poor land at that). We've had to fence all four sides, lay the water and seed it.
As we are still in the process of trying to improve the grazing, we are going to be asking the farmer whose fields back onto our house (and our paddocks) if we can pop our girls onto a fenced off corner of his dairy cow pasture. I'm hoping he won't want £60pcm for the privilege! I expect he'll let us have it for nothing, to be honest, as he often lets another local farmer graze his sheep on some of his other fields over winter (as he keeps the cattle indoors).
I have no idea on the local price for sheep grazing so I've been reading this thread with interest!