Yes, I saw that they weren't cheap! As you say, I think you will have to be reliant on someone disposing of their collection.
Remember seeing the Braniff 747's in LGW - occasionally saw the "orange squash" as well (the 747SP) as well as the odd DC8. Great days!
You've probably worked out that my "name" is also derived from a flight number used in the late 70's/early 80's!