It's not just that, it's also the manpower bill to be paid that will probably make this dream of 545 ships fall short. You have to recruit them and then keep them sailors and junior officers, so that they become mid grade petty officers and officers and finally chief petty officers and senior officers to fill all of those currently non-existent billets.
Read the rest of the article - its a major push to unmanned, or minimally manned, naval combat units.....
.......Third, Esper called for between 140 and 240 unmanned and optionally manned ships on the surface and under the sea, conducting missions ranging from laying mines, conducting missile strikes, resupplying manned ships, surveillance, serving as decoys and more.“They will add significant offensive and defensive capabilities to the fleet at an affordable cost in terms of both sailors and dollars,” he said.
“Earlier this month, the Sea Hunter prototype completed operations with the USS Russell, demonstrating that unmanned surface vehicles are technologically feasible and operationally valuable.”