Only a short drive to Portland. https://portland.craigslist.org/wsc/cto/d/portland-ford-model-roadster-pickup/7152375956.html
Here is a listing for what appears to be a clean and complete 1931 roadster in SoCal. It seems a little pricey but I really don't know the market and a lot depends on the actual condition, not what it appears to be in the photos and description. https://inlandempire.craigslist.org/cto/d/chino-hills-1931-ford-roadster/7154344464.html 1931 Ford Roadster - $16250 (Chino Hills) No rust, original convertible, title in hand.
I would say that is way over priced. I've been offered two roadsters in the last year, both were nicer than that at $12,500.
Check out "Old Cars Report Price Guide" (oldcarsweekly.com) They can give you a good place to start price wise. They have a 6 part rating system that goes from 6 (parts car) to 1 (points car)(pro restored). A standard '31 roadster as pictured above would go from $1520 to $38000. Without standing next to it I would say this one is maybe a 4? $7k?
Update: big things happening. I scored an excellent original chassis yesterday. I'm checking out a roadster body today. More details on the other thread here!