[Chris Goodwin]

XP cost to buy additional attributes = as listed in ITL p. 45; additional IQ does not give additional points to buy talents or spells.

XP cost to buy additional talents or spells:

25 XP times the minimum IQ for the talent or spell...

...minus 25 XP per point of IQ the character has above the minimum IQ...

...with a minimum cost of 100 XP...

...per point it costs.

An IQ 10 wizard learning an IQ 8 spell, base cost of (25 x 8) 200 XP, the wizard is 2 above the minimum IQ (2 x 25 = 50) for (200 - 50) 150 XP, so he pays 150 XP.

An IQ 10 fighter learning an IQ 8 spell... base cost of 200 XP, the fighter is 2 above the minimum IQ, for 150 XP, and as a fighter his cost for spells is tripled, so (150 x 3) 450 XP.

An IQ 15 wizard learning an IQ 9 talent that costs 2 points. Base cost of 225 XP, the wizard is 6 above the minimum IQ (25 x 6 = 150), for (225 - 150 = 75, minimum 100) 100 XP per point; it's a 2-point talent (100 x 2 = 200), but the wizard pays double that, for a total of (200 x 2) 400 XP. An IQ 15 fighter learning that IQ 9 talent would pay 200 XP.

This works for me.