I don't know how much $900 us is in Scotland but that's what I paid to have a 220 volt 50 amp cable run through my attic from one corner of the house to the other, plus a small breaker box and some bits of conduit.
It was the cost of the copper wire that was amazing. I think our regulations have really run up the cost of copper over the past 20 years. It's a common item of theft, in rural areas, and people are finding their copper wiring gone! If you have a large irrigation pump that's a $$$ piece of wire.