Hi Jen.
If 32 teaspoons is 80¢, then 1 teaspoon is
80/32 = 2.5¢
Therefore 1/4 teaspoon would cost
(1/4) (2.5¢) = .625¢
Note, just curious if you meant cents or dollars in your original post since we can't really have a half of a cent and certainly not .625 cents.