As a kid, all our posts were either farm cut cedar or locust, hand split or used intact. Some of those are still in use 50-60 years later but trust me, you don't want to drive a staple in the locust posts now. Unfortunately, the locust we have growing now seems to grow a little quicker and doesn't last as well. The last few fences we've put in used pressure treated posts. Lots easier to drive staples and quicker to get a bundle of posts than cut down the appropriate number of trees. Actually most of our fences are now tending toward a combination of wood and metal T posts with wood on the corners and braces and every third line post with T posts in between. That's fine with barbed or electric fence. If we have an all smooth high tensile fence, the cows will gradually push the T' posts over and make them lean just by rubbing on them.
I'm a few years ahead of you on the farming curve. My father and grandfather were full time farmers. I left the farm for a full time job but have kept my hand in on a limited basis but since I'm now looking at retirement, I'd like to up my time and effort on the farm. One big job that needs doing is rebuilding quite a bit of fence and while I'm still physically able to do most things, I can't work like I did 30 years ago so things I would have done then by hand will require equipment now. A good fence contractor can put up a fence quicker and better than I can. It will just cost a lot more. A sorry fence contractor can put up a fence quicker but it won't be a good fence and it will still cost more.
If you find the right young person to work with, I feel comfortable saying the money will work out.