Thank you for submitting your item for appraisal. This appears to be japanese katana of the 16th century, dated second year eighth month of Eishō 永正 (1506), part of the signature reads 備州長...佳 ..光. The condition will be an issue, but leave it as it is, don´t touch it, authentic patina is a plus in value. Some further research would be worth the effort. The estimate is based on similar sold at auction. "Asking prices" in the trade in Japan can be higher and vary.