ISBN Purchases

Any authors out there have an opinion on whether purchasing ISBNs is a waste of money for self-publishing authors? I’ve self-published a soft cover edition of “Menta-Life” using a createspace ISBN for FREE, technically making them the actual publishers; I’ve also published a hard cover edition with an ISBN that I’ve purchased from Bowker. Both editions don’t really seem to make any difference, aside from the hard cover being the favorite for its longevity. Other than pride in ownership, does anyone have any reason to purchase an ISBN when a free one is available elsewhere?

Menta-Life Full Cover