Walmart and Kroger, the two largest retailers in the United States, have both raised their prices for the BinaxNOW COVID-19 rapid tests, after an agreement with the Biden administration to sell the antigen self-test kits at a fixed price expired at the end of the year. The average number of COVID-19 tests administered per day is nearing record highs amid a surge in positive cases. The two retailers, along with Amazon, had agreed to a three month deal with the administration in September 2021 to sell federally discounted test kits made by Abbott Laboratories at $14. The cost of the two part self-test kits at Walmart has risen to $19.98, while Kroger is now selling them for $23.99. The big pharmacy chains CVS and Walgreens, are selling the tests for $23.99 a box, while other retailers are charging even more. “The program ended in mid-December, and while other retailers increased prices in mid-December, …