Considering we all have mono in our fishing kit, and wire on our tying tables, that's very expensive!
Yes, I have mono at my desk, but these really are superior for threading bobbins. If you consider that one last for about 4-6 months, 1.98 for 20+ years worth of bobbin threaders is not really that much to pay.
We get them from our dentist every checkup; helps fight plaque buildup on the teeth and wax buildup in the bobbin tube.
n additional factor to appreciate is that they will fit in the smaller tubes of older Materelli bobbins that will not accept the usual folded wire ones.