The reason for the extreme taxi price is probably that you paid an extra holiday charge on top of the already high night and weekend surcharge. However, it's always expensive.
Uber is 30-50% cheaper, but has limited availability because authorities are cracking down on it. As far as I know there's no risk for the customer, only the driver.
Some buses run all night, but not trams and metro.
For those flying to/from the smaller Sandefjord Torp airport with Wizz Air, you can save a few bucks by using one of the Polish transfer companies (you will take an old minibus with most likely only Polish people). May take a bit longer but they also offer driving you all the way to your destination address. Booking in advance is necessary. Example: http://www.polskibuss.com
Uber is 30-50% cheaper, but has limited availability because authorities are cracking down on it. As far as I know there's no risk for the customer, only the driver.
Some buses run all night, but not trams and metro.
For those flying to/from the smaller Sandefjord Torp airport with Wizz Air, you can save a few bucks by using one of the Polish transfer companies (you will take an old minibus with most likely only Polish people). May take a bit longer but they also offer driving you all the way to your destination address. Booking in advance is necessary. Example: http://www.polskibuss.com