Please calculate gross income and explain why the given amounts are included in gross income or not. Thank you!

Hopper works as an independent contractor (self-employed sole proprietor) for local businesses on weekends, and he often provides services in exchange for property. All of the following happened during 2019:

Hopper provided security services in exchange for $1,400 of car repair services, $2,000 of groceries, and cash of $6,250. The cash was mailed to Hopper in the form of a check on December 15, 2019. Hopper, however, was out of town for the entire month of December. When he checked his mail on January 1, 2020, the check was there.

Hopper also received a gift card in exchange for services he provided that could only be used for $500 worth of clothing at a local mall shop. During 2019, Hopper only redeemed $200 worth of merchandise on the gift card.

Happer had a total of $4,200 worth of legitimate business expenses during 2019, none of which were considered Cost of Goods Sold.

Determine Hoppers gross income for 2019 assuming that he uses the cash basis of accounting.