I am going to run an ad on my pre-ban ar-15. It was built on a 4 digit SN PWA lower with Bushmaster parts. Its a good shooter and I have shot some 3 gun with it. Its got a 20 inch military style barrel and solid butt stock currently. I also have the 11.5inch barrel with 6.5 inch flash hider and collaspable stock that was on the rifle before i began 3 gun. It would come with 10 30 round mags and 6 20 round mags.
PS its currently a legal registered assault weapon in California so this would be taken out of state by me or shipped thru an assault weapons dealer.
I would say with every thing you mentioned 11 to 1300 would be fair.But if its legaly transferable in california you could probably get way more there for it considering all you can get are those FAB10 type fixed mag ARs.