Samsung A series handsets (maybe A10e or A20) might be an option as well. Consider used like mentioned earlier, but keep in mind that the battery would also be used. Some of the Nokia/HMD devices are also an option, they're Android One handsets so updates should be sorted.
Anything (from any brand) below about $100-150 is likely to be rather limited in terms of specifications. Anything running Android Go edition is going to be a very low end phone. I'd avoid anything with less than 32GB of storage if possible (and definitely any 8GB phones). 8GB doesn't last long once the OS, updated software, and any browser caches or similar are taken into account.
Get one that's easy to find a good solid case. If it's for a young child, the phone's likely to cop some harsh treatment.