[Vicious]

I cant decide if i should buy Wild Arms 3, or Final Fantasy 7,8, and 9. My friend told me that i shouldn't buy Wild Arms 3 because i wouldn't understand the story because it ties in with the other 2 games, and i would like to know if this is true. I would like to buy Final Fantasy 7,8, and 9 because i've heard so much about their greatness, and they are also really cheap right know. I'd appreciate some guidance before i make a mistake and screw myself by buying the wrong game. Thank you.