I did a little more research. They're called RFID tags, looks like there's been a big push to implement them on more and more different types of goods, not just the higher cost items.

Still haven't been able to find much info on how much they cost.

alter_native

Bought a plastic food storage container today - guess what I found on it?

Signal312

I did a little more research. They're called RFID tags, looks like there's been a big push to implement them on more and more different types of goods, not just the higher cost items. 

https://lowrysolutions.com/blog/the-walmart-rfid-mandate-what-you-need-to-know/

Still haven't been able to find much info on how much they cost.
