You have not said what kind of resolution you need.
Austria Microsystems makes the Hall Effect absolute encoders in 8, 10, 12, an d 14 bit resolution (256, 1024, 4096, 16384 steps):
http://www.ams.com/eng/Products/Magnetic-Encoders/Rotary-Encoders
DigiKey has the AS5263 (12-bit) for $10.22 each: http://www.digikey.com/product-detail/en/AS5263-HQFT/AS5263-HQFTCT-ND/3028680