RE: What would you pay for this gun.....
If you can roll your own, then 550 would be a good buy.
If you are looking for brass, find out where your local LEO's go to shoot. They drop plenty of new brass shooting that qualifying course with the AR. Most dept.'s favor public rifle ranges like a wildlife management area. Call the rangemaster on site, sometimes police shoot on days the range is closed to the public. Bring a couple of buckets.