Don't know why they wouldn't sell EBR's. The one here in Michigan (Dundee) sells plenty of 'em. Last time I was there they even had a 50BMG rifle (didn't see the make/model) with bi-pod, scope, and camo finish perched neatly behind the counter.
The used firearm racks usually have more than their share of AR's too. I don't recall seeing any AK's or any other com-block EBR's. Usually not looking for them. I can tell you I've never seen a G3 on the racks there tho.
As for their Gun Library, I've seen LNIB Colt Trooper III's (6 of them given to a gun mag for testing then sold to Cabelas with a minimum of rounds through 'em) for $399 ea., Colt 1911's that were from private collections. Probably 20 years old and still in the box, unfired for as low as $699.
Other used goodies include Romanian .22 rifles (1911) for $65. A mountain of muzzle loaders, Browning A5's are not in short supply, M-4geries, Odd-lot hunting rifles (S&W bolt action in 300 win mag, that IIRC, was left handed) and plenty of .22-250 varmint rifles.