I am approached by friends and colleagues selling their used bassoons from time to time. I will post those instruments here. I also can help put you in touch with sellers of new bassoons. Please seek assistance when buying a bassoon from an experienced bassoonist and go with a reputable seller. I encourage students pursing music degrees to purchase Fox 240s but not exclusively. Bassoon prices are usually open to some negotiation. I will add some articles and information on purchasing as this page grows.
How old is the Fox (or Fox Renard) Bassoon? Handy table listed here:
No private sale of used instruments know of right now.