I have a atocha 4 reale grade 2 with Lima mint comes with certificate signed and stamped by Mel fisher and a small reciept that has details of coin also.But the cert was framed I took it out a found a sales reciept from butterfield butterfield caesars place dates in 1987 wondering if this coin has any monitary value today since someone told me they would give 200.00 for coin I figure I should sell ?