Depending on condition/playability I would say in the 3000-4000 dollar range, but maybe it's resonable to expect a little less for this particular model. 1A's are not popular in EU right now, for some reason (I don't know how it is in the US). They've simply grown out of fashion, again... Early/mid models from the 60s is another story though.
1964 - Masaru Kohno No.7
1999 - Lorenzo Frignani
2017 - Tobias Braun
Feel free to ask me anything about Japanese classical guitars.