Type 14s are very collectable, although not practical for shooting at the cost of 8mm Nambo ammo. Even though they don't usually bring the high dollars that Lugers and others do you should be able to get roughly $400-$425 for the pistol, holster, and magazines if all of the part numbers match.
I have one in parts that is in bad shape. Rusted, pitted, and has been sitting in parts for about five years. I read that if you press the hand grip just right, the gun will fire. I tried this, and the gun when "click". That was enough for me.
As with many of the war year production Japanese small arms the better quality pieces were produced during the early war years before the lack of resources and time constraints impacted the Japanese war effort severely. There are two different Nambu designs - the Type 14 and the much smaller Type 94. The type 14 is an odd cross between the Mauser C-96 and the Luger Parabellum. It was not as bad as often said. The main problem as you have stated is a very bad safety and a weak cartridge. The Ruger .22 rimfire semi-automatic pistol was inspired by the Nambu, but the Ruger is blow-back operated. If the Nambu had been up-sized to 9mm Parabellum and had a better safety and a few other problems fixed it would have been a decent sidearm for its time. Believe it or not the the Type 94 is even worse and had an exposed trigger sear which could be manipulated to fire the pistol regardless of whether the safety was on or off, certainly a catastrophic design flaw!