Wasted money

I have a Kirby vacuum cleaner which I bought about 3 years ago and hate the stupid thing. Cost me about 30 000.00. Salesman was good. The stupid thing was not even brand new. I asked if they will buy it back. What do you know “sorry we don’t buy back but you can sell privately. Had a look on gum tree and they are selling at such a low price. I wonder why. How do I get to be a good sales person and ask someone to part with R30 000.00