About how many levels can i get out of ARR/HW story if i start a new character at 60?

[Mizunoko]

Just asking because im making a new character on jenova, and i was just thinking if i level boost it to 60, but purposely don't buy the story for the sake of the exp unlocks for maps and story quests from arr and hw, does anyone have a decent guess at about what level i will be by the time i finish HW? Would i be 70 or maybe close? I can zoom through the story pretty quickly if i no life it for a few days, but at the same time if the exp added to my already boosted level isn't really going to get me very close to 70 i might just see it as a better idea to just story skip as well.

Keep in mind i already know the story i am a veteran player, so for me this would purely just be using the story quests for added exp. Also i'm not going to bother with doing potd/HoH to do the leveling instead because ive basically lived in their for the past month and the point of this question is more too see if this idea is decent enough to take a break from all the of those other methods. I may still throw in roulette running however. I would appreciate any guestimation or input anyone has to offer ^_^. Thank you.