Most of the time I use a 70/10 for piecing-either the quilting needle, or the microtex sharps.
For quilting, usually use 80/12, sometimes a 90/14 if the thread is a little heavier. Like others,
I wait for the needles to go on sale, or use a coupon when I buy them.

I use 90/14 for piecing I don't get needle flex when going over joined seams and the seams match up better. Now I am pressing my seams open and may go to 80/12. Always sharps, never universal and ball point for knit when garment sewing.

11 for piecing, for quilting it is dependent on your thread size I can use a 14-16 dependent on how thick my thread is