[Walmart] YMMV - Tile Mate 4 pack $10 [replaceable battery]
https://stocktrack.ca/?s=wm&upc=81903902063 - (I'm dumb, I didn't look it up by UPC # even though I had it.)
I believe it's the 2018 model but does have replaceable battery (model T5001).
A single tile on Amazon sells for $28.
Reason: updated price