The best reference I know (short of an actual bid from a local contractor) for remodeling cost and how it affects the value is Home Remodeling magazine's bi-annual issue on the subject, available free here

It defines every remodeling job.  For example a mid-range bathroom remodel is described as:

"Update an existing 5-by-7-foot bathroom. Replace all fixtures to include 30-by-60-inch porcelain-on-steel tub with 4-by-4-inch ceramic tile surround; new single-lever temperature and pressure-balanced shower control; standard white toilet; solid-surface vanity counter with integral sink; recessed medicine cabinet with light; ceramic tile floor; vinyl wallpaper"

Then it will give you an estimate of what that will cost, in every major metropolitan area of the county (including Portland, OR), and how much you are likely to recover upon resale.   Basic and upscale remodeling versions are also available which include the same cost vs. value numbers.  

I think you'll find some surprising numbers.