My last purchase was a roll of W&N at Joann's when it was 50% off.
I chose a bolt that had about half left on it.
I then got "end of bolt" pricing on the last 7/8th of the last yard.
(in other words 1/2 of 1/2 off on that one part of the bolt)
I mostly do QAYG, so on the bolt or in a bag doesn't really matter to me.
Price is my deciding factor.