Cast iron gutter refurbishing

Sometimes much cheaper to refurbish your washing machine, dishwasher etc. than buy a new one. Cast iron gutter is the same case. To buy and install a new one start somewhere 100-150£/meter. This is definitely not cheap. So, to find a cheaper solution you have 2 option. Change to pvc or refurbish. What is the advantage and disadvantage both?  That will be my next post.