Look, it's a cool little thing, but I hate when companies nickel and dime you for wanting to actually use their stuff. This wasn't a cheap toy to get. This was the upper rank of educational toys of the time.
But to make actual use of it you'd need not only multiple extension sets from the same line, but they also wanted to get you some electronics kits from the same company, AND have you buy into another company's offers as well.
Who had that sort of money?!
It was a toy for rich kids.