Amazon has my grandma's cookbook too, but it's priced insanely, at $57.00 for USED ONES, which were published many decades after the I have, which I doubt cost more than $1.00, in the 1950's!
When they cost that much, you know they’re valued. Used book sellers stay informed about their books. It’s a lot easier now with the Internet.
Sometimes you can do better on ebay, but even the sellers there have gotten smart about the going price of what they offer.