In my dojo the belts go:
White, White-Yellow, Yellow, Yellow-Orange, Orange, Orange-Purple, Purple, Green, Blue, Brown, Shodan Ho (Brown with a black stripe), and Black Belt.
The length of time between belts varies. The further up you go, the longer there is between belts. White to White-Yellow might be a few months while you might wait a year or more to go from Brown to Shodan Ho.
The belt colors will also vary between dojos.
The funny thing about martial arts, (maybe it's just around here but I doubt it) is that very little is consistent, even between two dojos of the same style. For example, even if another school does the same form as us, they may do some moves differently within it.
I pay $60 a month, but my dojo is just a little place. When we were bigger it was $90.