They used to be very common back up to the 1980s even and going for free, I had a couple over the years but I cannot see that value of post 400 quid in it unless it has its front and maybe its contents, bunks etc
It very much looks like Shoreham high ground including that distinctive tree line, the school is on the hill just to the right out of shot I would say.
its taken looking North.
I am guessing at this stage it was just a field with a few buildings