"He has a lot of ties and he is buying another one again!"
Translation:Il a beaucoup de cravates et il en achète encore une autre !
The English sounds funny to me. I would be more likely to say 'he is buying yet another one'. I don't think I would ever say, 'he is buying another one again'. If I did, it would mean that he had already bought another one, and now he is again buying another one, but in that case it would be more usual to say 'he is buying still another one'. Assuming the French is idiomatic, you need to make the English trigger more idiomatic.