cost saving estimate $($$$$s$).$ Here is what she provided you:

$1.$Questrom Directory is currently supported by in$-$house IT staff and hosted on internal servers.

$2.$Questrom Directory is open source and there are no annual software license costs to use the product however, a total of $$25,000$ per year is spent on operating systems, middleware, and runtime software.

$3.$The maintenance cost for internal servers is $$30,000$ per year.

$4.$Staff who support Questrom Directory are:

a$.$Storage$/$Virtualization Manager $($$$100,000/$year$),$

b$.$Programming Staff $($$$200,000/$year$),$ and

c$.$Systems Operations Manager for operating systems, middleware, runtime software $($$$150,000/$year$)$

$5.$The annual electricity bill for the servers is $$20,000$ which includes power and air conditioning

$6.$A competitive bid yielded the following costs, for:

a$.$Infrastructure$-$As$-$A Service $$100,000$

b$.$Platform$-$As$-$A Service $$150,000$

c$.$For Software$-$ As$-$A Service $$350,000$

Which approach $($Infrastructure$,$ Platform or Software$-$As$-$A$-$Service$)$ yields the greatest potential savings:$\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_$ and what is the $ amount$\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_?$