Old horns, like the Recording and others keep getting overpriced because, like old muscle cars and other cars from the past, there are people who will pay ANYTHING to get their hands on one and bid against each other.
Collectors can be their own worst enemy. There was a time RCA's Living Stereo and Mercury's Living Presence records were fetching hundreds of dollars for mint original copies - which weren't always superior to later pressings.
When independent record companies were able to obtain master tapes and began producing new copies on better vinyl and with better cutters, the prices dropped drastically.
If someone came out with a new Recording and other collector type horns, the bottom would drop out of the market.