Expensive ... unless you have a character with Alchemy skills, enough to be able to mix your own (spoiler board be the place to go for more info).-----
Visit http://wiz8.web1000.com/ to download a spreadsheet that allows you to enter in your spellcasters current stats, and the spreadsheet will tell you what spells the character can learn, or for spells that they are not yet able to learn, it will tell you how many points you need, or why your character can't learn the spell.
v2.01 released Oct 14, 2003