Answer:
$555
Explanation:
His net proceed is the difference between his net revenue and total cost considering how much was paid to the broker during purchase and sale.
Total cost at purchase = 200 * $18.12 + $30
= 3624 + 30
= $3654
Net revenue = 200 * $21 - 0.5% ( 200 * $21)
= $4179
Net proceeds = $4179 - $3654
= $555