A licensed Engineer can often provide an opinion in disclosure documents that a replaced piping system has an estimated life of 30-50 years. We can also petition the insurance company for an adjustment in rates (water damage is second to fire for loss value). This is especially important for condominium owners and high rise units. If the real estate agent is educated, he or she would point out the value in both time and disruption of not having to deal with a re-pipe. If you want to see the value increase, you'll need to educate the buyer.