Jofus, I have some logic for you to check. this is how I see it:
the saiga is 300 bucks roughly plus there are a million different AKM parts that interchange with 80% of the rifle, but the romak 3 is about 7-800 or 500 in kit that you have to assemble, and has less parts that are commonly to be found. the romak would be a nice build, and the saiga a nice conversion to do.
the other thing you are weighing is if you WANT a non-transferrable firearm like building the romak, vs having a russian AKM in 308 that you can spice up quite a lot.
both rounds are fairly close in price in bulk surplus, but I think there is a lot more options availible for the 308 than the russian round.
the saiga is still cheaper out of the box

that would answer it right there if it were me...