I'm interested in Modern (20s-50s)Firsts (Joyce, Hemmingway, Waugh, Steinbeck etc) and Victorian/Edwardian illustrated kids books (Rackham, Dulac, Parrish etc.)
If you wanna sell....
I know the feeling of having to down-size one's library though.
When we moved here, I had to sell, donate or piff some 400 volumes as they took up almost all the space alloted in our container!
Most went to good homes at a good price, but the worst thing about leaving tham was how so few people were interested in the same things I was!
I always have storage space for books though, so if you need a place to stack 'em let me know.