The 1890-O Morgan Dollar is pretty common amongst other dollars because of its mintage of 10,701,000. The price of this coin is not very high at all because it is easy enough to find nice ones even in higher conditions.  A 1890-O Morgan Silver Dollar in MS-60 runs for about $60 while unfortunately a MS-66 is just under $10,000. This coin is very average, and because there are no special VAMs of this year, there's not much to write about. Many of these coins have nice strikes and good luster, so keep a look out and find the best one that you can.

1890 O MORGAN SILVER DOLLAR MS/BU GEM US COIN RARE UNC    US $32.10

Morgan silver dollars 1890-O, 1891, AND A SPECIAL 1904    US $74.98

1890 O MORGAN SILVER DOLLAR MS 64 PCGS (#7389)    US $359.99