Three most recently completed auctions on GunBroker.com ranged from $410 to $425 to $450.
Several currently listed for $500 or more have been sitting with no bids.
Of course those "SOLD" prices don't include shipping/insurance/FFL Transfer Fee. Which makes them ~ $475 - $500 guns. Naturally, prices also vary by region.
So...Yes the one you describe is overpriced.
On the other hand, Norincos (like the Argentine 1927 Colts and Sistemas) are all-steel, quality 1911 clones of which there are a finite supply. They used to be $295 entry level import bargains. Nowdays they are sought after and I've not seen one for sale for below $350-$400 for quite some time. Prices will continue to rise.
Offer $450 (if the gun is in really nice shape). If you really want it, go to $500.
In the long run, you are talking beer/gas money ($50).