Using the output below, how much is each additional unit of skilled labor worth?

Variable Cells

$\backslash$table$[[$Cell Name,$\backslash$table$[[$Final$],[$Value$]],\backslash$table$[[$Reduced$],[$Cost$]],\backslash$table$[[$Objective$],[$Coefficientincrease$]],\backslash$table$[[$Allowable$],[$Decrease$]],],[$$B$$18$SemiAuto,$74,0,800,628\mathrm{.}5714,432\mathrm{.}4786],[$$C$$18$Robotic,$23,0,1000,1666\mathrm{.}6667,440],[$$D$$18$Manual,$0,-320\mathrm{.}253,500,320\mathrm{.}2531,1E+30$