Are carts all the same?

I see a lot of hate toward TenDollarCarts, mostly because they’re so cheap. But that alone doesn’t really explain anything.

What I’m trying to understand is: what actually separates their carts from the more expensive ones? What’s stopping other companies from buying the same products and reselling them for $20–$30 or more? It seems like if the exact same carts were priced higher, people would automatically trust them more.