I have a $10 (on sale) pair of New Balance nylon exercise pants which are wonderful for hiking in cold weather. They are somewhat wind resistant and have a mesh liner. I've had them several years and they have worn like iron--still look as nice as when I bought them. Admittedly they are not suitable for hot weather.
Back in the 1980's I (and every other hiker in town) bought a pair of Air Force surplus tropical weight (50% wool, 50% polyester) pants. The fabric is really like cast iron! The only wear is fraying of the cuffs' edge at the bottom. I think I paid $5 or $6 for them--best investment I ever made. I still wear them occasionally.
I bought a pair of Campmor convertible pants several years ago, another bargain ($20). The only problem with them was that the seat came unstitched, a simple repair on the sewing machine even for this non-sewer. I recommend that with any pants, you reinforce the stitching in the seat when they are new. One line of stitching is never enough in that stressed location! I decided after a couple of trips in them that I really don't like convertible pants and hardly ever use the convertible feature. With my legs(varicose veins and knee surgery scars), I generally avoid shorts. Even with stream fords, I kept the legs on. The convertible feature, for me, isn't worth the extra weight.
I tried REI and everything they had in women's pants had a low rider waist. With my ample (!) hips, that's a non-starter. Anyway, I really don't want the waistband of my pants to be under my pack's hip belt!