Re: neighbour dispute advice
Presumably it's a party fence and £170 as 50% of a quote for fencing doesn't sound too silly.
If you want to be awkward, ask for three written quotes and say you will pay 50% of the lowest or £170, whichever is the least. I suggest a polite letter. Really it would be better to do it through a Solicitor, but unless you happen to have one in the family it really isn't worth the hassle or cost.
Be careful, as boundary disputes can escalate into legal action, and in extreme cases the costs could be many thousands of pounds. Unless you are an eccentric millionaire, It Just Ain't Worth It.