I have a Gibson Maestro acoustic guitar. Really cheap guitar. I‘ve noticed there is a ringing on the 8th fret bar at the high e string and on the 12th b string fret bar. I see that the strings with copper wiring around it have worn a little and are showing a little black color, I‘m guessing from wear. Does string quality matter that much, or is it just that the fret bar quality differ a lot more between a crappy guitar to a mid-level to high-end acoustics?
That is normal wear on strings. Frets are typically made of the same material on all guitars, however some offer the option of stainless steel now. The quality of your strings will not effect your frets any differently than other strings. Frets wear over time from playing. Fret wear can be seen when you look at the fret itself and start to see grooves develop under a string or each string. You don't need to concern yourself with it for a while. If the fret groove starts to become an issue you have the option of putting it in the shop for a grind, crown and polish (which isn't that cheap), replacing the neck (only on bolt on's and set necks, although set necks are expensive to replace) or replacing your guitar. On a guitar like yours, once the frets go, it would either be a grind crown and polish or replace the entire guitar.
