Considering you get what you pay for...
an all metal semi auto rifle for 500 with working dust cover, forward assist, replaceable handguard that requires no special tools, and not needing to modify anything to get said handguard placed correctly...is within reason to me at least. The metal upper should in theory, add in the accuracy department as well.
It’s going to cost more working with metal, When yourinjection molding, you can afford to let your product go out the door for less.

Also, consider the cost of the handguard adapter nut and the original handguard nut removal tool if your ever interested in switching.