Thank you Hetty! This is exactly the kind of feedback I'm in search of.

Yes indeed, and I checked Amazon too - it seems the average price for Adult Colouring books on there is 6-7USD .. But I do feel like my mandalas are pretty unique (some of the cheaper ones on Amazon really look quite generic) and people would be willing to pay a bit more for a book full of them ;) Especially collectors of these types of things... I'll have to see =)