High prices for at-home COVID-19 tests are hitting the wallets of U.S. families who need them to get back to school and work — if they can find any to buy at all.

One restaurant worker in New York said she paid an acquaintance double the retail price in a sidewalk exchange for a test kit. A mom in Missouri said she’s rationing her last two-pack in case her kids show serious symptoms. Another parent is keeping her daughter home from school — where tests are required before returning after the holiday — until after an in-person appointment later this week because the $80 price tag she saw in online community groups was too steep.

Digital marketplaces list BinaxNOW kits — which include two tests — for as high as $75 (¥8,700), around three times what they cost at many large retailers. In a December statement warning against price gouging, New York Attorney General Letitia James said two-packs that are usually priced between $14 and $25 were going for up to $70 a package.