You can actually do research on the internet you know before asking on here.
Forged wheels are stronger. The idea is you can design a lightweight wheel and it will still be strong enough for normal driving. If you look at most normal lightweight wheels they are more prone to buckling or bending on a curb because there is less material making them light. Forged wheels make them stronger using less material. Obviously the process of making forged wheels costs more than normal castings or all wheels would be forged.
You need to ask the companies why certain wheels cost the price they do. Just because you dont like them doesn't mean they cant charge what they want.
and as for the ones for sale to which you are referring to, all metal can bend if you hit it hard enough the damage on those wheels would be worse if they were not forged not the other way round as you appear to be assuming.
