I bought 2 fish like that at Petsmart for like 2 or 3 dollars each...they were really beautiful though! But one of them was purple and blue, the other yellow and pink.
it is a guppy-Endler hybrid and A very nice one I would pay up to £10 a pair from a breeder / from a lfs no more than £5 a pair
the only problem is if there from a lfs they may not breed true / may not all be snake skin.
You have a very nice guppy/endler hybrid that could be expected to get about $5 for a pair at a club auction. As a reference, a pure bred wild type would only get about $3 at a club auction, I know since I often offer them at club auctions.