The accompanying table shows the relationship between the speed of a computer's CPU and its benefits and costs. Assume that all other features of the computer are the same $($that is$,$ CPU speed is the only source of variation$),$ and only the CPU speeds listed in the table are available for purchase.

The total cost of a $2\mathrm{.}5GHz$ computer is

$\backslash$table$[[$CPU GHz$,$Total Benefit,Marginal BenefitTotal Cost,Marginal Costs,$],[2\mathrm{.}0,$$$1,000,,$$$900,],[2\mathrm{.}5,$$$1,400,,,$$$300$