What type of Hall Effect sensor is cheap and common? for rotation sensor with magnet.

What type, what's cheap in Hall Effect sensors? Bipolar, omnipolar? I want to sense a magnet passing nearby on a plastic wheel.

You need to search thru a catalog (Mouser, Digi-Key, or Allied). For your application it probably does not matter whether it is bipolar or Unipolar. Prices range from $1.50 up. A switch type rather than linear would fit your use.

Think I found one thanks, A1101 LUA 3pin.
**broken link removed**