Will I need to make multiple purchases for multiple players on 1 system?

So, like the title states, I'm wondering if I will have to buy the game more than once in order for more than 1 person to play it on the same PS3.

My girlfriend and I both intend on playing this game on our PS3 and I'm trying to figure out if the game is locked to one account or if anyone can play it on the system (obviously each person has a separate subscription fee to cover). I just don't want to be told I have to pay an additional $40 to play a game I already own AFTER I've already linked the copy I own to her account.

And please, not to sound rude, but I don't want your opinion on how you think SE should run the game or how you think it works, I want an answer from someone who knows what they're talking about and isn't about to screw me out of $40 based on what they think instead of know.

You both can't play at the same time on the same PS3. So technically, if you don't plan on playing at the same time, you only need one account. Since one account can have multiple characters, you each can make a character.

If you are anal and want different accounts for the same PS3, then yes you would have to buy a second copy of the game, and set up a second sub. Which, IMO, is just wasted money if you don't plan on playing at the same times.