Tinned Copper Cable vs. Bare Copper Cable for speaker wire?

We always lean towards tinned copper conductor for our cables because we like our low frequency cables to last longer.

However, we do get asked for bare copper at times because it's a little bit cheaper. 

Wondering what your preference is between tinned copper cable and bare copper cable? 

Which do you choose, and why?
Why would you tin it to begin with your just adding another dissimilar metals and another point of compromise of signal.  bare wire is always better for transmission of a signal  and you can always cut a inch off if the bare wire becomes corroded.