Timex Jazz All-Stars show 1, on vinyl

In the local paper, the ad reads "Rare Jazz recording, All Star Jazz Show, sponsored by Timex, recorded live December 30, 1957, NYC. Only 200 copies pressed for private use." Everybody in jazz was there, and Steve Allen was the host. The seller is the original owner, but I don't know what type of turntable was used. He wants $400, which seems steep, but I don't know. What say you all?