INDIA: 1 rupee, 2010(c), KM--, experimental pattern in stainless steel, unpublished, with retrograde EXPT (for experimental) stamped across both sides into die, NGC graded MS66. This seemingly unpublished type is of an unusual design which was apparently not issued for circulation but produced by the Bombay mint as a "sample" or "experimental coin" in order to gain approval, similar in nature to a pattern or essai.
Estimate: 400-500 USD