you upgrade your citadel and run away from the UB. If it's that obvious the other team is wasting all their money on items, you (being the better player, upgrading your citadel) just have to make sure to a) not die, so they get no more money and 
take advantage of the situation with capture locks and citadel upgrades. Though i feel like 99% of this game has no clue when it comes to strategy. But that's it, at a basic level.. That no one seems to get yet.
that's all you do. the team that spends more money on items is the team that loses.
