Tuning Hand Pump Repair Business?

 I have gotten three years out of my $45 hand pump so far. But I know that it’ll need a rebuild before too much longer. I think there’s a video on how to rebuild it. At least I thought I seen one once. They give you a bunch of O-rings with it . The way I’ve always looked at things was, it is already broke so if I can’t fix it then I got my $45 out of it and will buy a new one if I have to.