$*$ One time cost: $$1,200$

$*$ Staff expense per week: $$720$

$*$ Time saved per customer trip for food: $4$ minutes $-$

Total time saver per week $($Thu $-$ Sat$)$

$=4$ minutes$/$customer trip $*505$ customer$/$day $*3$ days$/$week

$=6,060$ minutes$/$weeks

Recuperation timeline $($in weeks$)$:

$=$ Initial cost $/($Additional revenue per week $-$ Staff expense per week$)$

$=$ $$1,200/(($$$511,624\mathrm{.}2-$ $$23)/505/7-$ $$720)$

$=2\mathrm{.}59$