I discovered this price arbitrage by accident by clicking through from Google Flights! In my case, I paid with a debit card that does not have a foreign currency conversion markup and avoided the 1.99% fee that Norwegian assesses.

FWIW, I used the savings to book us into the Premier cabin.

Does anyone have any experience on whether seats DEF in row 1 are better or worse than in row 4 which SeatGuru describes as having limited recline?