You have to beat Seperate Ways w/ Ada Wong. You unlock Seperate Ways by beating Normal mode once. After you beat normal, go to extras and you will find Seperate Ways. Beat that and you unlock the...
1,000,000 PTAS
First Finish the game on normal and then beat Assignment Ada. After that you should be able to buy it for 1,000,000 PTAS
You need to pass the whole game on pro to hell mode.
If your game is for PS2,you need to beat Separate Ways,and Assignment Ada