Odd fear

I don't like using up things that have a limited / finite amount... for example, I have this lovely set of metallic eyeshadows that I got while I was in HK almost two years ago... I do not want to use it anymore for fear that I will see the bottom of the container and that would be the end of the shade that I like. The thing is, I've looked online and everywhere to find the identical set (or if not something remotely close to it...) It has such lovely colours I dont understand why I can't just find it everywhere!