Bolt and carrier worth $200
Complete lower as pictured worth $300
They all match, which is a plus for some.
$500 is unreasonable IMHO.
You are just pissed off because nobody gives a shit about your regurgitated Google search dingle-berries of wisdom.
I have eaten the equivalent in Army mess. Pretty damn bland on it's own, but if you bust up a bunch of cooked sausage into it and add pepper, it can be good to hook.