You're tasked with organizing a large$-$scale charity event, which includes the following tasks, their durations, and their dependencies:

Venue Booking $($A$)$: $2$ days, no dependencies $($immediate predecessors$)$

Vendor Selection $($B$)3$ days, depends on $A.$

Marketing Campaig $($C$)$: $5$ days, no dependencies.

Ticket Sales Setup $($D$)$: $2$ days, depends on $B$ and $C$

Event Programming $($E$)$: $4$ days, depends on $B$

Final Preparations $(F)$:$3$ days, depends on $D$ and $E.$

Now you want to expedite the project by $2$ days. Each task can be expedited by $1$ day at the following additional costs:

Venue Booking $($A$)$: $$350$

Vendor Selection $($B$)$: $$150$

Marketing Campaign $($C$)$: $$30$

Ticket Sales Setup $($D$)$: $$200$

Event Programming $($E$)$: $$300$

Final Preparations $($F$)$: $$100$

What is the least expensive way to reduce the total event preparation time by $2$ days, and what is the total additional cost?