Jane is a roofing contractor. Jane's friend needed a new roof but did not have the cash to pay. Jane's friend instead paid with a used truck that Jane could use in her roofing business. The truck had originally cost the friend $17,500, but it was gently used and only worth $6,000. Jane did not actually need the truck and ended up selling it to a used car dealer for $5,200 a few months later. Explain what amount of gross income Jane must recognize as a result of the truck payment and why?