Suppose that a rock 'n' roll band produces "gigs" for which it gets paid $5,000 each (the going price). Suppose also that the band paid $10,000 for fixed equipment. The four "musicians" each demand $400 for each gig (treat as salary, as if they were other people). They pay set-up people $100 per gig. Electricity is not paid for. Assume that each musician could be earning $200 per gig if s/he would become a "portable disc-jockey". If the band produces 8 gigs, what is its economic profit?