These were a one-time deal in a sales flyer about a month or two ago. They were originally $3.97 ea, which is a fairly decent deal. Most stores are probably out of them by now. I don't believe that this is a regular stocked items, so when they're gone, they're gone.
Edit: Wanted to add, at my local store, they had a display near the electronics checkout, with some SanDisk "Switch" drives. Basically made out of cheap plastic, but inexpensive. They had an 8GB model in various colors for $5.50 ea, and a 3-pack (two different sets of colors) of 4GB ones for $9.50 per package.
Probably going to give out flash drives at Halloween this year.