*Well, the price can be from 5 bucks up to few hundred bucks depend on the size and type of wood.
*Small pieces of wood you can boil in hot water, soak in bucket of water for few days up to few weeks depend how much the tannish color effect you want to take out.
*It will leech out the tannish color (yellowish, tea color effect) in your tank and create a nature look for your live stock.
*If the wood is new you can just power wash and put it your tank right away but for safety you would boil it to kill all unwanted parasite, bugs living in the wood (this mostly for huge, giant wood piece).