Brazil does not require a negative COVID test for entry and no quarantine is required.
In normal times, a coach ticket during the January-March summer season in the Southern Hemisphere usually costs over $1,100 and a business class ticket usually costs over $5,000. https://www.priceline.com/flights
JFK to Sao Paulo valid outbound dates: February 11 through 28 March: Entire month April 1, 2, 5, 7 through 30 May 5, 6, 11
Sao Paulo to JFK valid return dates: February 13, 14, 15, 16, 17, 20 through 28 March: Entire month April: Entire month May 2, 3, 4, 15, 16, 17, 18, 19, 22, 24, 25, 26