About 18 months ago I removed all the piping and ( uninsulated ) hot water cylinder from a 2 up, 2 down terraced before having a new CH system fitted there.
I didn't seperate the brass.
There was 28mm, 22mm and 15mm pipe.
I too wondered whether it was worthwhile taking it for scrap but as the scrap dealer was only a mile away I loaded the trailer with it not knowing what to expect.
They had a quick look over the trailer on entry, weighed the loaded trailer on entry then weighed it unloaded on exit.
Proof of identity was needed.
£110 on exit - I was suprised - definately worthwhile. I cant remember now but this load might have also included some old lead cable removed from the same property and weighed seperately.
I later took the removed radiators ( I think there were 6 in all ) to the same place and 2 scrap boilers and a couple of odds and sods ( 2 car wheels without tyres and two front brake disks ).
£85 was a suprise for me.
Guess it depends what transport you have and how far away the scrap dealer is but it was definately worthwhile for me.
I had to unload all the scrap from my trailer though whilst in their yard.
I used a scrap dealer that was used to weighing wagon loads of scrap and had a weighbridge at the entry point so I guess they are a commercial scrap dealer as opposed to a scrap yard.