Why not change them from -50% resource costs to acquisition timers. I'm sure we can agree the faction who owns Indar is REALLY op with their half price airships. Why not instead help the N00Bs and encourage them to use vehicles and maxes more by making their cooldown half length. So if your a BR1 you have a long time to practice maxes and what to and what not to attack, then, when the next continent is locked you could spend time looking at vehicles and finally air. It would be a nice natural learning cycle for the low BRs and make resources matter more, instead of making one faction EXTREEMLY OP with half price for a certain resource and just steamrolling tanks and other vehicles.
Timer reductions might work. I know for sure though that the bonus for a continent should not exceed 20 or 25%. 10% is kinda small but 50% is just too huge. Seems everything is in excess with SOE's balance. Overbuff or overnerf way too often. Smaller frequent adjustments would find a better balance. Mini-buff or mini-nerf until the sweet spot is found, don't try to drive a nail with a sledge hammer and hope it goes in perfectly.
