As they push the hoards to Battlefield 1, the Battlefield 4 DLC set goes for free. If you have Origin around then it is probably worth getting, as only the base game goes for $5 now and again, and traditionally the DLC keeps the price higher (as in you usually need the DLC to find populated servers)…
There’s also a cupon on with 50% off: origin50. Should make the base game a steal