Jacoby Company received an offer from an exporter for 30,000 units of product at $15 per unit. The acceptance of the offer will not affect normal production or domestic sales prices. The following data are available:

Domestic unit sales price	$21
Unit manufacturing costs:
Variable	12
Fixed	5

What is the differential revenue from the acceptance of the offer

$120,000

$630,000

$510,000

$450,000