If you model a deontological constraint as making certain actions unavailable to you, then you could be worse off than you would be if you had access to those actions, but you shouldn’t be worse off than if those options had never existed (for you) in the first place. That is, it’s equivalent to being a pure utilitarian in a world with fewer affordances. Therefore if you weren’t otherwise vulnerable to money-pumps this shouldn’t make you vulnerable to them.
(Obviously someone might be able to get some money from you that they couldn’t otherwise get, by offering you a legitimate service that you wouldn’t otherwise need—for example, someone with a deontological rule against hauling water is more likely to pay for a water delivery service. But that’s not a “money pump” because it’s actually increasing your utility compared to your BATNA.)
If you model a deontological constraint as an obligation to minimize the probability of some outcome at any cost, then it’s equivalent to being a utilitarian with an infinite negative weight attached to that outcome. Unbounded utilities introduce certain problems (e.g. Pascal’s Mugging) that you might not have if your utilities were otherwise bounded, but this shouldn’t make you vulnerable to anything that an unbounded utilitarian wouldn’t be.
If you model a deontological constraint as making certain actions unavailable to you, then you could be worse off than you would be if you had access to those actions, but you shouldn’t be worse off than if those options had never existed (for you) in the first place. That is, it’s equivalent to being a pure utilitarian in a world with fewer affordances. Therefore if you weren’t otherwise vulnerable to money-pumps this shouldn’t make you vulnerable to them.
(Obviously someone might be able to get some money from you that they couldn’t otherwise get, by offering you a legitimate service that you wouldn’t otherwise need—for example, someone with a deontological rule against hauling water is more likely to pay for a water delivery service. But that’s not a “money pump” because it’s actually increasing your utility compared to your BATNA.)
If you model a deontological constraint as an obligation to minimize the probability of some outcome at any cost, then it’s equivalent to being a utilitarian with an infinite negative weight attached to that outcome. Unbounded utilities introduce certain problems (e.g. Pascal’s Mugging) that you might not have if your utilities were otherwise bounded, but this shouldn’t make you vulnerable to anything that an unbounded utilitarian wouldn’t be.