Then make a decision. I would not buy a piano thirty year or older, unless some top brands. It is not only about the quality of the piano, also about the resale value. In addition, be aware of that there are some so-called “gray-market” Yamahas. (Read this page) http://www.yamaha.com/yamahavgn/CDA/ContentDetail/Text_WithCatMenu_XC.html?CNTID=12175&CTID=410010
What Yamaha says it true.