Not all pressure treated wood is the same. Some is treated better, and I searched around until I found some. You can go all the way up to a marine pressure treated, which of course the price is the highest.
I would use telephone poles, if the choice was available. Better than any pressure treated wood, IMO.
In regard to costs, I feel to many variables without knowing all the small details. Just like I said with the pressure treated. One guy may use the best, the next will cut every corner they can, from materials to labor. Key is to research. Lots of posts on here how to build, different materials used, etc.
