Yeah, I hear ya. Being an OCD kind of person, I
need to have a spare set of strings for every one of my 27 basses; 4 guitars; and a really old, long scale banjo. Which is a
lot of extra strings. I have 5 basses that currently don't have spares, but fixing that is my New Year's resolution. I do have an extra set of TIJF's for my '95 Alembic Epic, but... it's worn the current set for at least 15 years, and there's absolutely no reason to replace them yet. And, since I'm 73? There's a good chance I won't be the person replacing them. In fact, I might not be the one who replaces
any bass strings. Out of 27 basses, only one wears rounds (TI Jazz Rounds on a Gretsch Broadkaster), and 2 wear Roto TruBass88 Tape wounds. All the rest wear flats. And, one set of the Roto 88's is as old as the TI's; they still sound good, too. Even my guitars wear flats...As for the banjo? Try and find strings for a long scale banjo, sometime. When and
if - you do? You'll buy a bunch of them, 'cause banjo strings don't last very long...
But, having spare strings gives me a warm, fuzzy feeling, so... who cares?