To be honest though with the whole shutter life issue... That is just a theoretical life span. Just because they say 150,000 actuation's does not mean at 150,001 it will not work.
You figure many things are engineered with safety factors in one way or another. If the goal lifespan of the shutter is to be 150,000 you figure they have a set probability that has to reach or exceed that, generally something like 98% or something high if I remember from my prob & statistics class.
You figure a majority of all the cameras will have NO problem exceeding the 150K... If not go on to 200K or even 300K.
Now with the 1D series with the 300K shutter life or whatever they have, will the same standards... So you figure a majority must meet or exceed 300K... So 400K or even 500K is probably reachable on the stock shutter.
That is my educated guesstimate though... Plus a shutter is what, $200-400 to replace? Not all that terrible. Just adjust your used buying price accordingly.