But you're likely right (i.e. The bill would be large, but not so much due to the quantity (although that doesn't help), but rather the expectations of the grade/quality of work... and that labor cost.).
I think the point on the military budget helping is valid, though. Will it help "kill the issue"? No, but it would definitely help. Along with balancing budgets around based on what the society deems is priority, no? There is no one budget transfer that will do it.
But then... the issue is not only about pulling from other budgets, but also making sure the work is as efficient as possible. And honestly... the expectations aren't so sky high that it makes the cost beyond what any budget could aid. The ugly reality is our expectations in a mature, wealthy society like our's means the cost of infrastructure and their upkeep is a lot higher than elsewhere. That doesn't help, but most people don't even consider that reality.
Your prior comment about 'too many bridges' to deal with is true, but isn't it more an issue of not enough taxes to support it?
We have an infrastructure that was not designed for the capacity of people who use it, but between the premium to maintain/replace it and the continued burden of more and more users... not to mention inflation/unchanged taxes relative to the premium... we cannot keep up.
The term generally used as it relates to issues like this is OVERSHOOT.