I'm looking at wood for some raised beds.

Cedar 2x8's are 3x the cost untreated 2x8's. So, I'm wondering, how long
might untreated lumber last when it's used in raised beds? In direct
contact with the soil/elements. 2 years? 3 years? 10 years?

(I'm assuming ACQ, non arsenic treated lumber is still considered a no-
no)?

thanks