Price elasticity is fairly simple. If the TTC increases fares a bit, it'll mean more revenue. If they increase fares a lot (i.e. from $3.00 to $9.00, as you're proposing here) it'll mean less revenue since nobody will take transit. And no matter what, if they decrease fares they'll lose revenue, because the TTC (unlike Go Transit) isn't competing with a cheaper transit provider. They're competing with wheels and feet, which are either free or fairly expensive.What I certainly don't agree with is amnesiajune's concept that if we increase fares ~3x for really long-haul riders that it's somehow a cashcow, and improves the biz case of peripheral extensions. As if the same amount of riders will be there to pay that much. Or that if we decrease fares for short-haul riders the biz case for core area projects is ruined due to heavy subsidies. In both instances I think the complete opposite is the case.
Business cases basically ask "what is the cost of providing this service, and is that cost justified?" More revenue improves the business case, since the cost of providing the service is lower. Less revenue hurts the business case, since the cost is higher. A fare policy that decreases revenue on short trips and increases revenue on long trips improves the business case for the long trips and hurts the business case for the short trips.