It "depends"
- the area you want the maps for,
- the use you plan for the maps,
- the quality of the available maps, free and paid for.
When I use my gps rather than my phone with geopdf maps, I have only ever used free ones usually based on osm as they have been more complete and accurate than the commercial offering.
"Perfection is attained not when there is nothing more to add, but when there is nothing more to remove".