On the contrary, purple means that it's not Rare but uncommon instead.
Inscribable sephis axes aren't worth much these days and purple ones even less, only plat or two quite depending if you find someone who doesn't care about the colour.
If you mean perfect as in your axe with 20/20 +30, than all that would do is add the value of each component to your axe and then (at least) halve that total as no-one would be willing to pay full price for a 'perfect' purple sephis.
If you mean inherent gold q9 15^50, they sell for around 30kish.