I've changed the wording of the set-up for the final round, to clarify:
The four remaing players will play a maximum of 5 4-player games, with each of the spoils settings plus an additional flat rate. The first person to win twice is the tournament champion. The games will come out in the following order, Escalating, Flat Rate, Nuclear, No Spoils, Flat rate. Only as many games as neccessary to decide a winner will be played.