Make a list of books to be offered in the sales thread. If you make the "if these sell, I may list more" eludes that you have other books you would like to sell, and will lead to inquiries. If the books you are offering for sale are not interesting buyers, than why NOT give a list with prices of other available books. And ask that any interest in THOSE books should be taken to PM's.
If you dont want people asking about registry books, obscure the sets so they are private. No more questions, and no more peeking.
But to be rude to people asking about books is ridiculous IMO. Be happy when people are interested in buying them, I am sure you would much MORE bitter if they didnt ever sell.
And Bob, you know I like you alot. But you have been very short with me in the past as well. And I did find it a bit upsetting that someone I have spoken with, and had some good conversation could not be bothered to give more than a one word answer.