The frequency distribution of monthly breakdowns for a machine used in an assembly line of a company producing custom products is provided in table below:

$\backslash$ table $[[$ Number of Breakdowns,Prob. $],[0,0\mathrm{.}40],[1,0\mathrm{.}30],[2,0\mathrm{.}15],[3,0\mathrm{.}10],[4,0\mathrm{.}05]]$

If the preventive maintenance program is adopted, the probability of a machine breakdown is negligible, and the cost of a preventive maintenance program is $ $2,000$ ?per month. If the cost of a breakdown is $ $2,000,$ ?how much better $/$ worse off per month would the company be if it adopted preventive maintenance program?