$275 - $300 U.S. but only if it isn't an ex-jewelry piece. I see some wear and marks on the rim that have me concerned it may have been in a bezel and if it was, I'd bring the price down to $250 U.S.. Ribbit
Maybe it's the photography... but the obverse and reverse look so different as to be two different coins. The reverse looks MS and has better luster. Nice piece !
AU or MS -- can't tell from the pics. Therefore, it would be tough to nail down value as the range would be rather wide.