I know its poor form to mention such things but "unique" and "priceless" are both absolutes: something is unique/priceless or it's not. For example, if one thinks about two unique things it is not possible to say which is more unique than the other. (If one thinks about Difference Engines, since there is one in the Science Museum and one in the Computer History Museum, neither is unique.)
Usually when I see this sort of thing I shrug and remind myself that living languages constantly change. (It seems that "unique" has lost some of its force and is changing its meaning to something like "very unusual" or "very rare".) But two examples in one sentence apparently stirs the old fuddy-duddy in me to action...