The furnace isn’t working again

The other day i was thinking that i’ve had to have a heating and cooling company out to the house 8 times this year already to fix my furnace. I’m wondering if buying this furnace was actually a big mistake. The idea was to save cash, but I’m stuck wondering if that’s really what’s happened. I bought this furnace off a pal I know who does HVAC work for a living. He had taken it out of someone’s house who had upgraded their system, but the furnace was still new. He offered it to me for nearly nothing! I thought I had finally gotten a deal! A week later, I was on vacation, and the guy watching my house called me to say that the furnace had broke down. I couldn’t do anything until I got home, unfortunately. Nothing in the house was damaged, lucky for me. The time of year was not too hot and not too cold so all of the pipes and things were good. I had a heating and cooling worker come out and fix it and that was that. Not even a week later, I went to visit my brother, and don’t I get a call saying my furnace isn’t working again! I was so pissed. Every time I leave something happens with that furnace to make me all flustered. Not only that, I was putting out cash left and right to fix it. It was supposed to be saving me cash, not costing more! I know I made a bad decision in purchasing the furnace used. I don’t really feel like I’m saving a lot of money, and the hassle alone really isn’t worth it.