The message that you are getting - "Insufficient balance", means that you have the below function turned on (you've probably clicked "Yes, please" before profile visiting)
If you clicked "Yes", this means that Dux-Soup is looking and scraping emails of your 2nd and 3rd-degree connections. Dux-Soup is able to obtain the email addresses of your 1st-degree connections for free. However, if you wish to obtain emails of your 2nd and 3rd-degree connections you would need to purchase Dux-Soup Points.
If you do not wish to use this function and you did not intend to scrape emails of your 2nd and 3rd-degree connections, turn this function off by clicking "No, thank you".