Just note that completion time for Quest mode does not equate 1000 GS. I think in my case I was at around 500 GS when I completed quest mode. After that, it's all grinding arcades for enemy defeats... which is extremely time intensive.
And I suppose it's not difficult to rank up... but not everyone has fighting game instincts. If you can't defend, high rank AI will murder you. At least VF5 AI is more forgiving than Evo.