75 cents each, but couldn't enter value under $1 in description. Quantity discount to 60 cents for 20+.
I have 2 sizes. Smaller and more plentiful ones are 6 inches by 9 inches, 1.5 inches tall. Red, white, it blue colors.
Larger ones made of thicker plastic are 6.25 inches by 10.5 inches, 1 5/8 inches tall. Light blue color.
I also have a few old wooden ones that are mostly red, measuring 1 inch tall, 6.25 size, 9 1/8 long.
Both plastic styles have slots for name tags and most slots will either have writing on them or a smudged name that wasn't completely removed.
They came from an optical lab that cut lenses for eyeglasses, so many will have dried white polish powder. It can be removed with some scrubbing, especially after a cycle in a dish washer.