Wow! So glad that Battlefield 1 has been added to the EA Vault for PC! If you aren't familiar with EA Vault it is very simply $5/month (or $30/year) for access to tons of games and they just added BF1 and TitanFall 2!
Also they offer pre-release trials for many EA releases, and a 10% discount on digital EA purchases. They each cost $5 per month or $30 per year.