What phone to use

I am looking for an inexpensive phone (can be used) for OSM mapping. What phones have good GPS reception?

Those with dual band GPS, they came out in 2018. Started with Xiaomi Mi8, and then some others followed.
Partial list: https://www.xda-developers.com/dual-frequency-gnss-important-location-feature-your-phone-probably-missing/

For my opinion it would be better to use Huawei/Honor smartphones
Their Huawei GSM modules much more powerful, than Intels modules in iPhone or Samsungs modules in other Android phones