Hi,
I have many many kits......love em! I worked at my LQS and when we cut kits we did so generously ( I did!) and kits were the quilt top, borders, and binding. Backing is extra the majority of the time.
I like kits and my cupboard shows it, but they are complete with the backing fabric!
I haven't ever see a kit for sale that is cut out.....least not up my way.
When I see a quilt that I love the pattern, and the fabrics, and there's a kit of it done up.....out comes the cash, it's mine!