I buy mine at www.paperpieces.com. They are super nice to work with and I have never had any problems with them.

I purchased one punch from eBay, after that I purchased others from Hobby Lobby with the 40% coupon. I use mine all the time on card stock and the cards that come in magazines. I have put together kits for gifts or prizes. I have had mine for several years and have had no problems with them cutting.

I buy mine from Quilt Patis - definitely worth it - temporary plastic foundation to help make your Grandmother's flower garden pattern or diamonds.