Actually, now this time while purchasing the guitar you like do one thing:
Hold the guitar from its base & Look at it's Fret board TANGENTIALLY from the base (not from the neck).
You'll Observe two things:
1. The fret seperation (It should be equally spaced & Getting brorder at the base)
2. The distance (height) of the strings from the fretboard.
Always play & see the guitar below 12th fret White mark. If it twangs its the Finishing problem of the guitar, dont buy it.
"It's All A Game, Avoiding Failure,
When True Colours Will Bleed..."