Have you had a chance to play it - if it sounds OK it probably is - check the height of the strings above the fretboard - mostcheap banjos have the action set so high that there is no chance of any buzzing but can often be reset to make a platyable instrument.
I think you should probably steer clear of this one & look for a banjo you can try for its tone and playability. If you play guitar or any other string instrument you should be able to judge the feel of a banjo.
Good luck & if all else fails, why not have a go at building one - I did many years ago and now make them to order for friends etc