Well, considering that you can set money aside, the decision is probably going to be not between Gear and Vault, but between Gear+Gold and Vault+Silver. I would much rather have the former — triple Gear is already very consistently able to hit $8, so adding in a Vault results in overkill turns while you lose out on the very useful set aside ability of Gear and give your opponent the benefit they get from Vault. There are turns when you would actually rather want the Vault over Gear for sure, but those are less common than the turns when you want the Gold over the Silver which is every time.
