Where can I buy Norton Antivirus in a cheaper price?

To whom it may concern,
Good day!
I have a trial Norton installed on my desktop. It will expire two days from now.
It really works on deleting viruses, so I want to buy it. However, I could not afford a higher price than $50. The one I owned is worth $60 for the full version. Do you know where I can buy Norton antivirus in a cheaper price?
Thanks!
