When it comes to any upgrades it depends on how much you extra you spend on that ship and durability then compared to getting a new ship.
As of now spending 12 points on upgrade is a headhunter Tie Fighter so if you count up your upgrades and it comes to 12 to 24 points you might want to take a look into what it is on.
Now on some list builds spending over 12 points on upgrades is justifiable such as the Buzzdroids. But for most lists if you can get another ship for the points on upgrades you have spent it is best to ditch the upgrades and get another ship.
