How do I report this income from goods sold?

Selling 4 collectible guitars on behalf of a deceased friend's family. I will get 10% of sale price. If a guitar sells for $5,000, I get $500 and forward the balance to his family. ALSO, there will likely be PayPal fees. How is this to be reported? Would that be a Schedule C and enter the $5000 as cost of goods sold minus $500 retained as commission? How do I deduct PayPal fees?