backing up and restoring from only 1 replica?

[Mike Koh]

It has been suggested to me that we could save a fair amount of time and 
money by taking a snapshot of only 1 replica (so every third node for 
most column families).  Assuming that we are okay with not having the 
absolute latest data, does this have any possibility of working?  I feel 
like it shouldn't but don't really know the argument for why it wouldn't.