MK$\text{'}$s Cellphone Store is a small company that has hired you to perform some management advisory services. The following information pertains to $2023$ operations.

Sales $(1,400$ phones$)$

$$1,400,000$

Cost of goods sold

$602,000$

Store manager's salary per year

$209,000$

Operating costs per year

$230,000$

Advertising and promotion per year

$30,000$

Commissions $(3\mathrm{.}5\%$ of sales$)$

$49,000$

What was the variable cost per unit sold for $2023?$