They had 3 BDK at Costco in Fresno. Went back 2 months later, still had 3 machines there, one of the flippers on the demo was not working. The playfield was dirty, and looked well played.
Don't know how many they sold, but I'm sure the Fresno ones went back. I remember at the time you could buy a used one for the same price that these were going for.
Zizzle, 70's home model EMs, have any of these types of pins ever appreciated. I passed on a HUO Fireball home model for 200 bucks that was mint last year. Didn't have the space, and didn't really do it for me.