Do you have a Half Price Book store in your area? They always have great old cookbooks. I think they may have an online store too but I like to actually browse through the cookbooks.
Yes, and I used to visit used bookstores in most every city that business travel brought me to. I make an annual pilgrimage to their main store on NW Highway in Dallas.
I go by HPBs on a regular basis, and usually enjoy searching for bargains.
Certain selections are mostly forgotten by the young stores clerks, and they often wind up in the clearance section.