Norinco 84s 5.56 rifles average around $1000 (+ or - $200). They are pre-ban ('89) and should have all the "evil features" (pistol grip, threaded muzzle, bayonet lug). New in the box the rifle should be equipped with a sling, flash hider, (3) 30 round mags, cleaning kit, oil bottle, bayonet and manual.
The 84s isn't really an AK74 but simply a rechambered 56s which isn't a true AK47 or AKM since the Chinese never adopted the AKM stamped receiver pattern. Instead the Chinese ditched the original AK47 milled receiver and came up with their own (thicker) stamped receiver. Along with the thicker sheet metal the Chinese also used a different rivet pattern unique to their Kalishnikov family with the exception of their AK74 5.45x39 clone which uses the standard Soviet/Euro rivet pattern.
Regardless they are fine rifles. Mags tend to go for $25 and more but are still pretty easy to find. I have 2 post-ban NHM90 5.56 rifles which are nothing more than neutered pre-ban 84s rifles that were caught in Customs and made to be compliant with the 1989 ban. It's hard to pick a favorite but my Norinco .223's are right up there, accurate and reliable. They'll feed a variety of ammo and for jsut plain fun it's hard to beat the inexpensive Wolf.
As always, there is the possibility of the rifle being a converted post-ban. It should have an integral cleaning rod with unaltered bayonet lug. Since you mentioned AK74, I'm curious whether the rifle is marked as such? If so I'd say something is fishy (very fishy).If the rifle has MAK or NHM anywhere on the receiver or trunnion it's not a pre-ban and worth considerably less money.