Emma Jones contracted with the publisher of a GMAT test preparation manual package to sell the review materials at college fairs. She can purchase the book from the wholesaler at $70 per package, with the privilege of returning all unsold packages and receiving a $70 refund per package. She plans to sell the packages for $280 each. She also knows that she must pay $3080 to the organizers of the college fair for the booth rental. She will incur no other costs. She must decide whether she should rent a booth. Calculate Emma's operating income if she expects to sell 30 packages at the upcoming fair.