The JAM Decats are similar to the Zep Racing ones in being a Stainless steel one - that being said, its not known how resilient they are for British roads, but the Zep ones seem to have faired well. New they weren't that expensive, same sort of price as the Zep Racing ones at around £150? So I would say £100-120 is a reasonable price if immaculate, but that's just a random estimate