Yugo's have long been considered very good AK's, but the problem is that nearly all of them you'll see have very little Yugo in them
Most of the ones around will have an American made reciever, and an American trigger group ( which most U.S. sold AK's have long had( but also probably an American made,non-chrome lined barrel ( which even the newer Romanian WASR's are now getting) . All good stuff, but NOT Yugo.
Another point, the Milled thing is just a bunch of hype,milled AK's are simply more expensive and heavier. That's about it. ( And I own a few Ak's, and have owned many others, including the Mac-Daddy's, the now highly-prized Polytechs, both the milled Legend, and stamped Type 56,).
I've also owned one of the underfolding Yugos ( Century M70, as I recall, but sold it for big bucks back during The Great Assault Weapons Panic of '08). It was a nice rifle, but it was quite heavy ( and that's with only the 1.6 mm. stamped reciever) and the metal underfolder was the non-ergonomic pain in the ass I was warned that it would be ( but I aaallllllways wanted an UF, so I just haaad to get me one
If you just love the rifle, and have the money burning a hole in your pocket, well, I understand that. But if you're looking for ONE good SHTF rifle, then I honestly recommend you look at something else, like maybe an already converted Saiga. Take a look at Classicarms and see what they're doing over there.