It could be a palm print. I show this coin as $20 in MS 63. I don't think it grades that high. Looks like a scratch between 2 and 3 o'clock on the obverse. I can't tell if there are some hits on the jacket, and the letters in Liberty seem mushy. Then you have that print on the reverse which detracts from value. It's not in a slab, did someone crack it out of a details slab?
The "fingerprint" is too straight; normal ones have curves and whorls. Sort of reminds me of those bag toned Morgans, where the sulfur-ridden canvas led to straight lined toning.
MS70 often gives that tone/lustrous look but it is market acceptable. I think the reverse lines are other than fingerprint. Hey, it's $26. If you like it buy it. The world will keep turning.