Its my 172 Cup, the belts on their own were about £14 for the cambelt and about £11 for the Aux I believe, certainly not much more. They were bought from Unipart a supplier I have used for many bits and altho I can't remember the belt manufacturer I did check that they are a company who supply many OEM's.
you just changed the cambelt and not the idlers and tensioner? Jesus-H-himself!!!