Hhmm i see your point but to be fair 90% of Cliosports have had them changed , and the standard system is so expensive most have aftermarket systems on!
Plus whoever you sell it too is buying a Cliosport at the end of the day, they arent after a diesel van so any exhaust upgrades should be favoured !!
But if you do decided you couls always ask to save the old unit and put it on when you sell it, i know its time consuming to not cut it off but its there mate !!