It depends on the hair and what you get used to.
Both of my kids have sort of fine, soft hair. My neighbor's kids have very course, thick hair. They have never owned a Chi. They use a $19.99 Andis brand from Target which they love. It is for course, thick hair.
So, our Chi (which is 3 years old) finally broke. So, I ran out and got the cheap one from Target. It takes a full 10 minutes to heat up. My DD said it does just "okay" on her hair. I think once you get a Chi or a similar iron, it is hard to be happy with another? I don't know. I thought for sure that since my neighbor's thick hair was tamed with this cheap one, it would do wonders on my kids' hair. Not so. But my DD wants her hair VERY straight and maybe the neighbor's kids are satisfied with "sorta" straight.