It would depend on if "salt and money" is considered a single thing or two separate things.
A: Would you like a sandwich? You can have ham and cheese, or turkey and tomato. (= pairs of things that are considered one)
B: Ham and cheese is what I want. (= "ham and cheese" considered singular)
A: What would you like on your sandwich? We have ham, turkey, cheese, and tomato. (= many individual things)
B: Ham and cheese are what I want. (= "ham" and "cheese" considered two things)
In this case, I think "salt and money" should take "are"; they aren't a pair of things that make up a whole, but two individual things.