You could do this . Took this from a gardensite ( Copper Rings Standard - Pack of 6 rings approx 10cm / 4" in diameter £16.75 ) thats about 72 inches of copper Now goto b&q or the like . and get this ( Streamline Black Label EN 1057 Copper Tube X022L-3 22mm x 3m, X022L-3 ) thats 118 inches for less right now use a jigsaw /saw and cut inhalf longways now you got 6meters 236 inches ,you have saved about 3 pound and gained 164inches almost making 20 rings for the price of 6ish sorry if my maths is out but hope this helps .