$.$ You can purchase a residential building lot for

$($a$)$ $$60,000$ cash, or for

$($b$)$ $$10,000$ down payment and month$-$end payments of $$1000$ for $5$ years.

If money is worth $7\mathrm{.}5\%$ compounded monthly which option should you choose $($option a$)$ or $($option b$)?$