Based on what I could read on the label his description seemed very accurate, so I went looking for info to see why he thinks it is worth so much. Based on what I found at the link below, diatonic versions of the bandura from this era were never made in large quantities, and many were destroyed during and after the war. In other words, they are pretty rare and there has been a resurgence of popularity for them recently. So maybe he isn't crazy!
http://en.wikipedia.org/wiki/Kharkiv-style_banduraJodi