If you plan to buy Goldfish then do not do it like going for blind date. Make sure you know what types of Goldfish are good for your tank and how many you can house in your aquarium. Always research about fish you plan to buy. Don't believe everything your pet store staff telling you.
Goldfish are one of the aquarium fish types with longest Lifespans. Fancy Goldfish types live 10-20 years but those single tail types like Common or Comet goldfish might live 30 to 50 years. There are over 120 types of fancy Goldfish so it's not easy to generalize their lifespan. But When you know which breed