Persona 4 is my first Persona game and I really love it. I wanna get Persona 3 and Persona 3 FES but there's something I wanna know. Do I have to get both or does FES have the game plus the bonus content in it?

FES has the original game and the bonus content.

FES does have some changes from the original Persona 3. I get the impression they are all changes for the better though.

FES is basically just the enhanced version of Persona 3 + the sequel/expansion. When you start the game up you'll be asked which you want to play - the journey or the answer IIRC. The journey is the main game, the answer is the expansion.

Thanks for the info guys. Now I have one question, when getting the true ending in P4 is the fight against Margaret part of it or is she the secret boss fight?

She's the secret boss.

I think she only appears in the second play through doesn't she? I never ran into her in my first game even though I completed the S Link for her. That being said, I might have completed it after the dungeon when you'd run into her.

Thanks for all the advice guys. I got P3FES and I like it. But now I have another question.

I heard there were costumes you could get for the characters that were different than their normal clothing and it would show. How do I get them?

Is that in P4? I never found any costumes in that game. In P3 you can get armour that you find/buy which changes appearances.

FES has bonus costumes, not P4.