price of secondhand roof tiles

[Helen888]

I would be grateful if anyone knows the going rate for secondhand roof

tiles, a chap has asked a friend of mine if she is interested in

selling the tiles  on her barn roof (it needs a new roof as half

has fallen in but  as its massive there are enough intact tiles to

cover a house roof i think. The tiles are those red, terracotta

coloured , flat square ones about 8'' by 8''. Would be really grateful

for any pointers.