Thanks for the welcome.
Actually I don't remember ... it was a long time ago. A store that sold them plus a lot of smaller robotic toys was going out business and was selling off their remaining stock so I got it at a really big discount. We also bought a bunch of the smaller toys but resold them at that time. I'm sure the retail price was several thousand dollars at the time.
The only thing I remember the price of from those days was standing in line 2 hours to buy an Apple II + at $2,000 (48kb memory, 1 floppy drive) that became obsolete a couple of months later.