Cost calculation

I spent about 20 hours doing my analysis and writing my report, my salary is $33.65/hr so the costs would be:
Wage           $673.00
Benefits (28%) $188.44
Total          $861.44

Background information

I am a 21 year old student from the Netherlands. I've been interested in computer security for about 4 years now, and have been doing reverse engineering for about 5 years. I used to have a webpage that contained a course in reverse engineering by requiring users to solve different puzzles, but this site has been shut down by Trialware Professional Association even though nothing illegal was performed there. We asked people to add functionality to binaries we wrote ourselves. Nowadays I do not have a lot of time to practise my reversing skills so they have become a bit rusty.