If you're looking for free/low cost legal help in the Portland area, you may want to see if the law school at Lewis & Clark has any legal clinics that might be able to help you out. I know they have a very low cost clinics for other matters, like starting up businesses; they may also have a clinic for small disputes, like yours. Alternatively, the Oregon State Bar has some good information for consumers about legal topics, along with links to where to find low cost legal help, here: http://www.osbar.org/cao.
*Please understand that this is not legal advice, and please do not treat it as such.*