I’m getting the impression that cedar is viewed by many as the only option when it comes to pergola construction. I get the argument when it comes to the rafters, especially, as they generally lack tight spacing (like decks have, for instance) that might otherwise provide stability.

However, would it be a bad idea to still go with treated pine for 6X6 posts? Seems like that’s one area where saving the money could be appropriate, particularly if just planning on painting vs staining.