I bought a ROSWHEEL LCD Waterproof 14 Functions Wired Bike Computer 81491 from China via eBay for $3.95. Naturally it takes a while to for delivery. The instructions were in Chinese. I think I’m happy.
If you want to get it into setup mode when you first install the battery. At that point you need to work quickly. You can expect to repeat the setup a few times till you get the hang of it. Once in setup one button advances the setting, and the other button advances thru the steps of the setup (speed units, wheel circumference, initial odometer setting).
There many videos on the net illustrating how to set up other bike computers. Watch those for further suggestions on how this one works. There I learned there that it’s a good idea to wrap all the extra wire around the front brake cable.
The wheel circumference is in units of 10mm. I had issues getting the magnet screwed on to the spoke, so be careful about that. I suspect if you pay slightly more you might get a better design for that, and 1mm units for the wheel circumference.
Later, I recalled the Google Translate app claims to translate little snippets of text. It is much improved since I last tried it. Now, it works! It’s tedious. It’s very cool.
I bought it from this eBay seller.