There are lots of free patterns on line so when I buy a book it's because there is something unique in it.
-----But, when I was doing demo's with the block of the month and only had 1 color combination, not many sold; we only ordered a dozen and maybe 25 peole would come for the demo. When I did extra blocks with a different color combination we had to reorder, sold many more. Quilters are visual people.
I don't know if this helps.