If the kid really needs them, I'd do it, even if it were for cosmetic reasons, but if it's a matter of having "perfect" teeth, no.
My older kid had an eye tooth coming in at a weird angle, but otherwise, her teeth were very good. The first ortho wanted to remove the baby tooth that was causing the eye tooth to come in weird, and then put her in a full set of braces for two years. Dh took her to that consultation and he asked no questions. $7000. The second one really wanted to do the same thing for the same price, but when I pressed, he admitted that there was a Plan B. We had the baby tooth removed and he made a small appliance that pulled down on the eye tooth. It came in perfectly in four months, less than he predicted, and for $1200.
When he was trying to get me to go for the full set of braces, he showed me the panoramic x-rays of her teeth superimposed over the theoretical perfect teeth. They were nearly identical, but he kept pointing to minute imperceptible differences in the justification. I happened to know his long-time office manager personally, and after he left the room, she quietly told me that my instincts were right and there was no reason for my kid to have a full set of braces.
My sister had a son with genuinely crooked teeth. She got six opinions, and they ranged from Invisalign braces for 18-24 months to let's break the kid's jaw and keep him in appliances forever.
So, get multiple opinions, and ask about Plan B if you aren't convinced of a need for braces.