Swell computers has 12 obsolete computers that are carried in its inventory at a cost of $13,200. If these computers are upgraded at a cost of $7.500, they could be sold for $15.300. Alternatively, the computers could be sold "as is" for $9,000. What is the net advantage or disadvantage of upgrading the computers? 56,300 advantage $1,200 disadvantage 55.400 disadvantage $3,000 advantage