Finn is considering whether or not to do a masters degree for the next academic year.

The fees for the course are $9,000$ and books would be another $400.$

He is currently working $35$ hours a week in a local business at a rate of $13\mathrm{.}88$ per hour. He would have to reduce his hours to $15$ hours a week for the full $39$ weeks of the course. As he would only be working $2$ days a week, his travel costs to work would fall by the current $40$ per week to $20$ per week. He won't have any travel costs to University as his house is within walking distance.

What is the opportunity cost for Finn of doing the masters?

Give your answer as a whole, positive number.