Be patient. I got mine on here for $4500 shipped. No Mlok slots but does have the small dia. bolt --if you don't get one with the small dia. bolt and you go to do a barrel change, well, you'll be in another $400-$500 or so. Army rifle has single stage trigger, so does mine. Same cost but swapping one will be expensive as fuck so get the one you want. The single stage is real nice, it's all a matter of preference. Or in my case, availability.
If you don't get the Mlok slots but want 'em and plan to change color anyway, LRI does it. I'm gonna go ahead and do it because the work plus the Cerakote job using the 20150 Coyote Brown is reasonable. And my barrel and can are being fitted by Elite and they'll be colored to match so why not? It had to be done anyway to fit the brake.
I think the trifecta for barrels with this rifle is gonna be the .338LM, .300NM and .308. .338NM if you want mag length VLD's and don't mind giving up some downrange performance otherwise. But I think those three will be most useful and a .338 can suitable for all. Add 6.5CM of course if you have that in your arsenal, I don't.
Top this puppy with a Leupold Mk5 7-35x or maybe the Mk8 3.5-25x, depending on how this vet discount thing goes they got going on.
Oh, same time I got mine on here for $4500 another one sold for $6000 but came with the hard case, drag bag, .338LM, .300NM and .308 (the trifecta) Mlok and was Barrett brown I think w/suppressor mounts. REALLY nice if you ask me, basically the $11,000 Mk22 kit! Good deals pop up here all the time.
Good luck. It's one badass of a rifle for sure. Certainly impressed me when it arrived.