I will wait for others to come along who have experience with selling the adjustable handle version as I don't know. I'd guess around £200, it looks pretty Ok condition.
Did you check completed listings?
If you only want it for off road use, I would get the cheaper version called the 'terrain' which has a fixed wheel. That would be better for genuine rough territory.
The Urban is built for town use really.
I sold mine btw because I have an Easylife sport, the same design but sturdier and bigger - more weight at the rear - it holds my five year old and my one year old at the same time
The MB was lovely and much lighter to push, BUT it fell over backwards with heavy shopping on the bars, and also sideways when big boy tried climbing up.
The Easylife is much cheaper prob because it's heavy, but it is so much stabler imo.