Free: Contests & Raffles.
I buy the same style chinese made ones at walmart. $12.88 and they are super light weight. I would rather buy a new pair each year then drop 200 plus on the top brands. That's just me though.
Prana zions are a nice hiking/climbing pant that would work well for early season hunting and they wont break the bank. They dont make them in camo though. If you shop around online for them you can find some pretty good deals. Picked up a pair for hiking this summer and ive really liked them.
I have had great luck with cabelas microtex pants. For a "hunting" pant. Durable, nice pocket setup, and quiet.