How was it sporterized? If it still has the mum I would restore it if possible, as it was a battlefield pick up and very collectible. Japanese and U.S. soldiers defaced the mum as it was the seal of the Japanese Emperor.
If its not restorable, its still a fine rifle. According to Hachers notebook the Type 38 Arisaka was the strongest military bolt action made. It could not be overloaded to the point of blowing up the action, In another test a plug was welded into the barrel, the gun fired, and the barrel stretched and tore into two pieces, but the action was still serviceable and rebarreled.
I see sporterized Arisakas going for about $100-$200... But I wouldnt pay much more than $100. I only paid $200 for my Type 99 with the mum!