We are using a modified PokerStars.com tournament poker points calculator, adding the additional variable of "final table weight", giving an additional bonus to all players that survive to the final table of the tournament.

Formula
10 * sqrt(Number of Players in Event) / sqrt(Player Place Finished)) * (1 + Log(Buy In + .25) * Final Table Multiplier

Player Index = (Number of Players in Event / Player Place Finished)
Table Index = (Total Tables in Event / Number Tables Left When Finished)
sqrt = Square Root