I second the age verification
As far as well priced AEG's go, Ares also gives you some pretty good bang for your buck along with a great variety of M4 platforms to choose from. They have solid guns for starter prices. You can start there, get a feel for what role you want to play, then branch out to other platforms from there.
If you're really wanting to go AK though, I would go with LCT. I would have said Real Sword (I've owned a couple and they are incredible) but to my knowledge the company is now defunct. LCT however is a great substitute.
My personal favourite is VFC for the external quality. But that's the higher end of the spectrum.
But yeah due to laws we can't give you info on where to buy them until you get AV'd