I am better equipped to determine the $$ number than anyone else on this board - I ran a project team for several years that, among other things, did a mission/function/task analysis, and restructured and re-equipped the numbered fleets, including 5th.
5th fleet, by the way, was established long before our present conflicts.
Since our government exists to provide for the common defense, the 5th fleet budget (which is far smaller than you imagine) is a reasonable expense. The argument that we should, or could, spend the defense dollars on other priorities ignores the mandate for that defense, to include establishment of a Navy (but not, I should point out, an army, which was envisioned to be raised in times of need).
We have chosen to spend less on defense these days than we have at any time in our national history.
We have already answered your question through our spending levels and priorities.