Well, today I am going to replace the insulation on the target for the first time. The original insulation lasted about 7 months and about 4000 shots. My the main setup that I was using was a 70 pound parker and darton bow, 31 inch draw, 2317 aluminums, 5 blade 135 grain inner loc broadhead. I bet it would have lasted much longer using a two or three blade head. It cost me about $26 for the materials that I had to replace. So it cost around 2 cents for every three arrows that I shot, or about $2 for every three hundred arrows that I shot. I think it was probably worth it.