Few of us always have fresh basil on hand unless we cook every single day and go through our little supermarket basil plant or clamshell before the dreaded gray starts spreading on the leaves.
But even those of us who cook often run into the basil supply flow chart: need basil --> run out and acquire basil --> use a bit of the basil --> throw out what used to be lovely basil because it wasn't used up in time --> need basil again.