CMU Founation – Inward Displacement – Repair / Brace or Replace

While I do not make it a practice of specifying how a foundation needs to be repaired, I am curious what guidelines you guys, and or professional contractors, may be using to decide when a block wall can no longer be braced, and will likely need to be rebuilt? Basically trying to decide at what point I need to start letting a potential buyer know that the wall may be past the point at which bracing (which is very common around this area) is a viable option.

On the same subject, how much inward displacement in a block wall is acceptable (bracing not necessary) if the underlying causes (grading, gutters / downspouts, etc.) have been taken care of?