Actually, Habitat for Humanity came and took many things out of our home before it was torn down. They sell the items they recover in their ReStore. Habitat was able to take windows, cabinets, the hot water heater and many other things. There is an article about it below.
Yes, you may even want to ask the trades that will be constructing your new home to see if they will give you a "credit" towards your future purchase. Also, cooper is very valuable right now and many older homes have cooper pipes that could be traded for your future home or recycled.