how about a basic wireless od/mile model ? don't have smart phone and don't need anything but speed and distance and low budget
thats where most start off at about $25.. LBS being aTrek Dealer they are what are in that shop..
I have antique Ciclomasters , they just need a battery and re inputing the wheel radius.
single row LCD, metal threaded O ring sealed, battery compartment, so its pretty much deluge proof.