I don’t know if you live in a urban or rural area.
Where I live there are lots of barely used and even unused ARs for sale on sites like armslist.com.
But if you don’t know the different brands and options very well, and if you can’t completely trust the seller, buying a pre-owned firearm can be chancy.
Talk to gun people you know, talk to small gunshop owners, talk to Freepers. For $750 you can get a decent model.
Though after yesterday ammo prices and probably the gun prices too are going to spike again.
Fightin Whitey, you are absolutely right! The real advantage of buying one used is; you can get all the upgrades the owner has added for pennies on the dollar. Many buy a very nice rifle, equip it with every device available, then, needing a few dollars, sells everthing for less than he paid for just the rifle.
The last gun show I attended had dozens of AR type rifles.