One point to consider that I neglected to state in my earlier post is that of warranty.
When purchasing new, you are the original owner. Register the shaft when you buy it,
save your purchase receipt and your shaft is warranted for life. No muss, no fuss.
Purchase a shaft on the secondary market that someone is trying to 'get rid of'
and you're pretty much stuck with what you get, ie, no guarantee, no warranty.
If your equipment means something to you, your investment is worth protecting.
HTHs, KJ