they pretty ok last about the lenght of 2 jobs then chuck em...I have a buddy in Perth "Gary" who now buys bulk cutters from John he has a company called polyvisual
here
http://www.polyvisual.com.au/
talk to him when he makes a new order you can get it in his bag and save on postage costs with him..very cool guy and has tons of cnc experience he has operated 5 axis machines and also can hand write g-code designed and built his own machines too..nice little factory he has there ...great spot to get acrylic...I used to raid his skip for really useful bits and pieces...still use some of his off cuts as spoil boards today..