Sgt of Arms

[Klem]

Isn't buying piece-by-piece usually the most expensive way to get one??

No - You got a very cheap gun so all kudos to you. Hopefully it's not going to fall apart down the track.

Another way is to buy a clapped-out 223 and swap out the barrel for a new one. Plus Grendel bolt and Magazines and Bob's your uncle. For the price of a barrel, bolt and an old AR you can improve the precision to new. Then replace other key parts down the track like the trigger.