Me and my gaming group were thinking about introducing a new homebrew rule to our game: option a) after a really important event of the campaign OR option b) after spending a certain amount of XP (something like 50-60) on skills and talents, each character gets to increase one of his/her attributes. He/she can't raise an attribute over the cap of 4 / 5 if kin or profession attribute /6 if both, as per creation rules.
Our best option was b), but in any case we wouldn't use both for obvious game balancing reasons (we like the gritty feel of the game and don't want to change it in a considerable way).
We don't think introducing the option to buy the improvement with XP for the same reason - to balance it with skill improving cost (5x new skill rank), the cost of an attribute improvement would be too steep.
Well, we'd like to know your opinions about this: does this house rule sound reasonable enough? Any suggestions?