[hcobb]

Currently there is an overwhelming advantage to buying IQ at start.

So just give a bonus skill point each time a character spends XP to raise IQ. The exponential increase in attribute costs will keep seasoned characters from abusing this while allowing all types of initial character designs to be viable. It simply removes the when of IQ increases from the balance. You can increase IQ at start or during play and you get exactly the same final result and cost.