If flexibility isn't an option then you're going to need a hard cap in place a.s.a.p. One man's definition of reasonable could vary greatly from another man's. 50K cr. seems like a likely limit. That would mean earning 150k in two weeks in addition to whatever you have to purchase to progress in game. The 15th anniversary cars will not be eligible for selection because not everyone will have access to them and they are reportedly mildly tuned versions of their regular counterparts. That may change if we get the game and they are found to be identical to the regular versions of the cars but don't count on it.