Updating Mac Norton Antivirus

Hi,

 

Having just got an Mac to use at home, I was wondering about the update function on Norton for Mac products.

 

Having come from pc at home, I know that I can update Norton 360 to the latest version whilst my yearly subscription lasts.

 

So, am wondering, that if I managed to get a old version of Norton Antivirus 10 with a years licence for a few quid instead of paying for the latest version, would it let me update itself to the latest version of 12 or would I have to purchase the new version from Norton?

 

Would prefer to get the old Norton Antivirus 10 version for a very cheap price instead and update it, rather than have to pay out just to get the latest version. Mind you, have got voucher code for getting 65% off Norton Antivirus price, so can't moan that much about paying for the new version!