Is your Bernina a piecing machine or a midarm quilting machine? If you are using Aurifil, you should compare the yardage of thread on a spool to say Mettler or any other GOOD thread, you will see that Aurifil is cheaper by the yard than others. So that $10 a spool is not a bad price. I was told not to use Coats and Clark in my machine because the wax coating on the thread is not good for my machine. I have a Husqvarna Viking Designer 1, so I spent a lot of money for my machine, I am going to use a good thread, and if they recommend a good thread for your machine then there is a reason why.