Guess it is called "supply and demand" . Keep in mind this really only a balloon and has a lifespan of only a few weeks. I'd have trouble spending even $40 for a balloon let alone $80.. It's a great idea though.
I use to deliver flowers for a part time retirement job to support my hobbies. Once I delivered a huge balloon at a gal in an office and if you tapped the balloon it played some very annoying people singing Happy Birthday. So when I gave it to her I tapped it and it started playing. You should have seen the look, very annoying, but I told her not to worry it will quit in about 2 hours! Then you should have seen the look on her face!!! Actually it only played the song three times, which was more than enough! I think she threw something at me as I left, didn't wait around to see.
Those balloons were close to $30 and they didn't do anything but drive people crazy.