Why are you going to the main dealers? If your diy then take the radiator to a motor radiator manufacturer [motor-rads - see telephone book, there will be several 'radiator' experts near you]and they will make a replacement radiator. Most will re-core the old radiator [replace the fins] and repair the upper and lower tanks. Your radiator will be returned as new and at a fraction of the cost for a brand new radiator. The price will be minimal compared to a garage quote. Many garages simple take your radiator to be repaired on your behalf - you will pay the garage for doing the haulage on your behalf!