This is a Current (And Airspeed) Sensor for $1.45.
I raised this question a while back, and was reminded again by the Post below which asks how to stuff all of this into a small box. (Beautiful Glider)
Small planes should remains a primal focus because they reduce the real and regulatory risks and allow broader participation in more fields/parks, etc...
So I'm offering a size reducing part - add a current sensor in exchange for the whole pitot/airpressure spaghetti.
The Airspeed theory is simple - at a given RPM, power consumption is proportional to airspeed, The faster the plane, the less the motor consumes to turn the prop. One can either detect the rpm, or determine that ESC's are essentially RPM = Throttle. Then a bit of data collecting will show the relationship.