I'm having trouble deciding what to go for next. I have good magic damage and sight, meh armour, okay melee.
Somehow my poll didn't apear in me post but it was Spellbook, Sword, Armour and Explore
If you're more concerned about dying from mobs, I suggest that you should attempt to purchase an armor set suitable for your set-up.
If you're in need of more magic damage, go ahead and aim for the Spellbook (although I would suggest the Darktoad Spellbook as it's quite beneficial for its life-steal ability)
Sword, eh, I wouldn't recommend it until you at least purchase an armor set capable of improving the weapon's potential.
Explore, go ahead, no one's stopping you. *winks*
What do you think?