i "borrowed" it from work. (got tons of it laying around) any metal supply shops will have it though not sure on prices. you could also try plumbing stores, you might be able to save some costs and just get 304 grade. i wouldn't think you'd be able to buy nickle plated copper tube because as soon as you bend it the plating would flake off. which means you'd have to bend it all up, and send it off to be plated.