Q226: A friend of mine in an epic game needs a massive boost to spellcraft. I told him the 765,000 gp +120 item with four different types totally isn't worth the cost. How to do it?
Have leadership, epic leadership, and epic spell-casting.
Use a ritual epic spell with lots of low level caster minions supplying one spell, and have the spell be Fortify to give you the largest bonus to CHA you can pull off with it lasting 1 month (that's 72 DC towards duration).
Repeat for every type of bonus you can. You leadership score should be significantly higher, and you now have hundreds more minions to donate spells to your ritual casting, allowing you to cast more powerful versions of each bonus. (repeat this as needed)
Then, when your leadership score is over 9000, make an epic spells to boost INT massively, giving you a bonus to spell-craft equal to 1/2 the massive bonus to int.
Of course by this point you can give all your followers SR 9001, DR 9001/+9001, and +9001 to each armor bonus, permanently, so you've already won the game. I have lost the game.