I was in the same delema when i first decided i wanted to get a RPK.
I ended up shelling out a bit more money for the Yugo and never looked back.
It has a brand new barrel on it so the bore is 100%. The barrel is also thicker than the romanian version, which gives the m72 better accuracy in my opinion. It also has the cooling fins on it which the romanian version does not.
Plus the riveting on the m72 is top notch. It is built on a solid Nodak Spud receiver. All the m72's that i have seen have had all matching numbers.
The fit and finish is hands down better than the romanian's. The entire m72 has a evenly applied park finish. The AES's that i have seen are a bit "rough around the edges" as with all romanian rifles.
Also, isnt the bi-pod that comes with the AES's not a true rpk bi-pod?
Iv read alot of threads about people changing out the bi-pod it came with for the real thing.
(sorry i had a bad bad experience with a romanian WASR, which was also converted from a single stack mag)
Overall when looking at the two, it seems like more time and work went into the yugo rpk, which also explains the extra cost. But in my opinion, its worth it.
Iv seen some kick a$$ AES's on here, dont get me wrong any rpk is a good rifle
Drakin