Copper is not made by Gauge it is made by oz. 16 oz is the standard 3' X 8' sheets. Would be afraid to ask how much a sheet cost.
McMaster-Carr sells it by thickness, not oz or guage... a 3'x8' sheet ranges from $261 for 0.021" to to $2116 for 0.187"
Best I can measure, the copper tips on all three of my Rushton paddles are about 0.03". A 3'x8' sheet of 0.032" from McMaster is $385. Luckily, you can order it in smaller pieces!
Aren't you glad you asked?
Dan