These 6 sided dice aren't regular cubes. The're oddly wonky. But amazingly they are totally fair. That's because they are isohedral, meaning every face can be mapped onto every other face through a symmetry of the object.
These objects have a handedness. Which is to say the mirror image of a dice is not the same as the dice! So here, you get a set of 2, the right-hand version and the left-hand version!
Also, check out the skew d12s.
Price = (the 139th prime number) pence = 797 pence = £7.97