Ask HN: Cheapest Laser Micrometer Vendor for recycled filament manufacturing?

I need a laser micrometer to measure 3d printer filament. Which vendor sells the cheapest one?

I need it for community project: https://medium.com/endless-filament/make-your-filament-at-home-for-cheap-6c908bb09922

Currently I use a dial guage with roller contact point to measure filament diameter and fetch it brought Arduino like this: https://youtu.be/bqzcS68T7tQ

I found one for $2000+ http://filamentmachine.com/?p=39

Are they supposed to cost this much?

I just need accuracy of 0.001mm and range from 1mm upto 5mm.

Any alternative approach you can suggest? Please suggest some non contact approach. And why this tech costs so much?