It varies and you can't always find the same price. The last price I paid for Nanos on Amazon was 5 for $17. Aliexpress is cheaper than that (that's where they're usually under $3), but I can't always wait that long.

My bad: forgot we were talking 32U4. Here's a link for $2.70: https://www.aliexpress.com/item/32846843498.html?src=google&...