I think a good Army Surplus store is your best bet for inexpensive wool pants. They may be from a few years ago, not made in the US, and they are getting harder to find, but there are still good bargains if you can find your size. You can increase your chance of success if you are willing to buy a bit big and have them tailored too. It will add to the cost but a good tailor can fit them exactly the way you want them to fit.