--どんな望みも叶える、 とまではいかないまでも 、魔術師としては十分すぎる程価値のある物だ。
It can fullfill every wish, ...., As a magician it has an incredible value.
What does that mean?
Has it any function in this sentence?
I think it is:
と言うまでは=Say something to that degree
行かないまでも=It may not work
と言うまでは行かないまでも=Even if you can't say it with certainty
「Phrase A + とまではいかないまでも + Phrase B」
means
"(It is) Phrase B if not (totally) Phrase A."
This expression means that it would be an overstatement if the speaker used Phrase A to describe something, so he would just describe it using Phrase B.
"It is more than a valuable item for a magician if not something that will fulfill every wish."
