They're not. You're being ripped off.
Yes, because it is made out of gold. It's a joke please.
That is up to you. Remember however that all the fancy goldfish can crossbreed with one another. If you are going to be buying/keeping expensive fancy goldfish then you would most probably not want to cross breed them and thereby loose the value of the fry.
contrary to popular belief, most goldfish do not have a stomach!
Comet goldfish are the average pet, although you can now get funnier types such as (my favourite) Celestial goldfish.
If they're keep together - the RES will have an expensive meal !
A telescope eye goldfish is in the fancy goldfish type, and most fancy golddfish get up to a foot long (with proper care).
Most likely not. If there are goldfish, then there are definetely going to be predators. Goldfish are small, and one predator could eat about 5 goldfish. It's very unlikely, but possible.
Goldfish are not aggressive fish. They most definitely do not kill people.
It is normal most every goldfish does it, don't worry.
Yes. A COMMON goldfish is extremely endangered. At most 2,000 left!
A telescope eye goldfish is in the fancy goldfish type, and most fancy golddfish get up to a foot long (with proper care).
Comet goldfish- they're the most common because they're "feeder fish." Comets also get most deceases.