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.
I tend to drop them or misplace them when I'm tying but they serve a couple of other purposes for me. Being whip finishing challenged, I'll make 3 to 6 wraps of thread over one and put the tag end through the loop and pull it under the wrapped threads to finish the head. Picked up that one from rod building. I also use them to pull legs through the soft foam bodies and poppers that I use.