The article needs to be updated. Glock 17's are going for $500 (not $350), if you can find any Glock in 9mm. It seems that 40S&W Glocks are easier to find and one can buy an after market Lone Wolf 40/9 conversion barrel. (Of course you'll need 9mm mags).
The AK47's are not <$400. They, too, have suffered price increases due to demand. I've seen them $>600 for the standard wood stock models. You'll pay more for the tricked out models. The biggest strike against the AK47 at this point is the unavailability of ammo. Can you believe it? What used to be plentiful is now hard to get. In contrast 5.56NATO to fuel an AR15 is easier to find. AR15's are $1000-1100. And I do not find them difficult to use in contrast to an AK47.
If one finds an AR15 too difficult to operate, get some training or use the 10/22 or (better) a Marlin bolt in 22lr which is even easier to use.
The AR is not more difficult to use than the AK, but it does have more buttons that can confuse an inexperienced user. The AK has a lever that is the safety and is located at the bolt. Push the lever, cock the bolt, then fire. Lever up for safety and magazine release at the magazine. That’s it.
The AR on the other hand has the bolt on top of the gun, the safety on the left hand thumb, and the mag release in front of that. I take both my AK and AR shooting when I go with my friends. I have never had to show how to operate the AK more than one time, but the AR always invokes more questions and blank stares when people are trying to figure out which switch does what. No doubt it is an easy gun to operate, but its design is not quite as simple as the AK.
In addition, I occasionally have problems with my AR jamming, but I don’t have problems with my much cheaper and much lower quality AK (probably because everything is so dang loose on that gun). There is no doubt though that the AR is a much tighter and better quality gun and the availability of ammo is better than 7.62x39. I’ve been waiting for 3 months now for my bulk order for my AK.