I don't know about your server, but on my server the Abyss Crystals needed for the +61 SP enchant are ridiculously priced. The enchant comes out to be a little over 1k gold if I remember correctly. Maybe you think that's cheap, but I sure don't. :-p The staff SP enchant is pretty comparable price wise, which is kind of weird...
And Pold is right on the money about spirit. While a mage shouldn't necessarily gear for spirit, with the Molten Armor glyph, spirit really helps up your crit rating. The staff wasn't a huge upgrade for me, but it was pretty decent. Before I was using
The Kirin Tor dagger with
Telestra's Journal with the +50 SP enchant on the dagger. I think I lost about 10 hit, but I gained the spirit and a tiny bit of SP with the staff, plus it's purple. =x