I just saw an advert on Facebook:
Gee, I'm pretty sure all NASA images (and all Hubble images, obviously) are PUBLIC DOMAIN.
Buy rare Hubble photos
Buy high resolution fine art images printed and framed from rare NASA Hubble Space Telescope archives. Free shipping.
But best of all, the advert has an example image: the Eagle Nebula image, probably most famous and un-rare Hubble image ever.