I need to measure water through a tube.

Specification: 0.25 ml/s - 1.5 ml/s (this can be relaxed to 0.40 ml/s- 1.15 ml/s)

I came across a few flow meters/sensors which could work but they're all pretty expensive (> 160 USD) - but was directed to pressure difference flow-sensors.

After the third page of google I couldn't find something small (which integrates well into a PCB fixture setup) and inexpensive (<150 USD).

Can anyone help?

Help Wanted!