....for an insulated steel sided and roofed hangar which
is more affordable to build- post style (pole barn) or traditional
stick (framed walls)?

The last few times I built a structure similar (not a real hangar yet) the post
built came out cheaper for materials. Since I built them myself I didn't
factor in the labor. I'm not much of a carpenter but the post went together
faster for me than the stick. It may be the other way around if you hire a
professional.

My current project is a 40 X 16 storage shed using wood poles/posts, and steel
studs in place of the 2Xs. They are cheaper and straight. Should look kind of
odd when I get to skinning it with all those cleco's sticking out the side
waiting for the rivets G

Urethane foam insulation may cost more but it goes in so fast IMHO it's worth
the cost to let someone else do it.