Somebody may have beaten me to this but here goes:
After using a few Birchwood Casey Shoot-N-C targets I have made up some uber cheap targets by cutting squares of the unused part of the black targets and sticking them onto an A4 sketch pad book, with 80 sheets, that I bought for only 99p. The original targets are sticky backed and it's a shame to waste all that useful blank area. 99p for 80 cheapo targets, with different sized squares ( you could cut any shape that takes your fancy) Sensible recycling??