Yes the $1.89 was what the solid brass G1/2 barbed fittings cost. The flow meter is from Seeedstudio.com and cost $9.50 USD.
It's a typical magnetic flow meter which outputs an electrical pulse with every revolution. The signal is a simple square wave so its quite easy to log and convert into liters per minute using the following formula.
Pulse frequency (Hz) in Horizontal Test= 7.5Q, Q is flow rate in L/min. (Results in +/- 3% range)
The flow meter is silent wen in operation and from what I can tell, does not introduce any noticeable restriction in flow. I am pumping a cooling fluid mixture through it that is similar to common automotive antifreeze so its slightly thicker than water.
Using a CPX Pro (jingway 1200) pump from Dangerden.com I am getting an output of about 400lph on average which is consistent with testing from other independent testing labs.
I have tested this setup on another pump (Thermaltake 500lph) and the results from it are also consistent with other results I have seen.
I really hope some of you use this in your projects. If you do please email me (charles gantt at themakersworkbench dot com) a link to your project.