As you can probably tell already, i love AK rifles. The design of this rifle is nothing short of superb. I consider the AK pattern the greatest firearm design of the 20th century, if not the entire history of firearms. There are two versions of AKs: ones with stamped recievers and ones with milled recievers. There are pros and cons of each.
Milled Recievers are the nicer AKs. They're just too expensive. The cheapest milled AK on the market right now is a Polish model available from Century Arms for about $650. These guns feel much more solid than your average stamped AK. the bolt carrier just feels so much more solid.
The other design features a stamped reciever. Stamped reciever guns are less expensive than milled guns. These are available from several countries such as Bulgaria and Romania. because they are made utilizing a flat piece of steel that's then bent, welded, and riveted into shape, the whole gun is much cheaper to build than a milled gun. It may sound like a lot of work, but the cost of materials and machine work is still cheaper than taking a block of metal and having it sit on a series of expensive milling machines that drill out all of the necessary gaps in the metal.
It is widely held that stamped AKs are not nearly as accurate as milled reciever guns. Milled guns don't twist and flop around like stamped guns do, which leads to better accuracy.
If you're on a budget, go ahead and get a stamped AK. They're a little loose feeling, but they're much cheaper, costing only about $400.