You don't unlock create-a-class until level 4. You unlock Ghost at level 55. This means you will have 50 levels (4-54) in which you cannot use Ghost. After that, you can spend a prestige token on Ghost, and you will literally never have to take it off.
50 levels of your entire Black Ops 2 career in which you cannot use Ghost. You aren't allowed to complain about this.
Edit: 50 levels + all prestige levels before 4 where you don't have create-a-class unlocked
If you play this game to be "good", im happy for you. I play to have fun (im not very good) and I hate being reduced to a red dot on the enemies radar and being blown up by a tube or grenade when I am somewhere no one can legitimately see me. Cheap or whatever, being invisible is how I enjoy playing. Gonna suck to get that 55.