We're interested in buying a narrow strip (perhaps 3.5 metres wide) of land next to our garage and tapering along our driveway, to make it easier for people to turn round as we are the end of a private driveway / cul de sac. Currently the land is unused, overgrown with weeds and plants, and would not be usable for any sort of building / planning permission type venture as after about 4/5 metres it slopes steeply up to a narrow path and then a steep drop back down to more houses. We approached the council who initially seemed open to the idea, but have now asked us to say approximately how much we would be willing to pay, which as we have never bought land is a bit of a tricky question. Does anyone know what sort of price of metre they might be expecting us to offer on a narrow unusable strip of basically waste land?

When looking for prices it will vary for the area & if the land is allowed to be built on or not.   I would advise going to a few estates agents & they should be able to give you a few instances or sales they have had sold recently. We did this when we enquired about some brown site, unbuildable.

Some estate agents deal with farms and the like and have land agents working for them who will be better versed in land prices, my friends husband was one and its always interesting talking to him.

OH said to remind you there will be legal costs and the council may well expect you to pay both yours and theirs.

I also did this. An extra strip of 4m to extend our garden. Council charged us £500 and we had to pay legal costs. This was in 2005 ish.

My brother brought something similar to what you describe 3 years ago about 4metres and council asked him something similar and he offered and they accepted £450 with fees I think  it was about £2,500 approx as a total.