Retail values are $17.00-$36.00 for circulated coins depending on the grade.
1883-S $30 to $250,000, 1880-O $27 to $70,000, 1921-O does not exist.
The 1860 o seated liberty dollar is a valuable coin, but it depends on the condition. It could be anything from 50 to 3000.
A typical (MS-63) Mint State 1880-O Morgan has a average retail value of $375.00 if certified by a known grading service.
its fake o silver dollars were made in 1799
1899-O Liberty Silver Dollar: good condition-$11.00, mint condition-$180.00
Look on the back below the DO in DOLLAR. It could be black or there could be a small O, S, or CC mintmark. Value as of June 2012: No mintmark:$52 "O" mintmark:$156 "S" mintmark:$52 "CC" mintmark:$540
Assuming the coin is circulated retail values are $17.00-$30.00. This date/mintmark Morgan is common.
The 1880-O Morgan Dollar, in MS-65 Grade, is so listed in the Red Book.
1899-O Liberty Silver Dollar: good condition-$11.00, mint condition-$180.00
Please look at the coin again. All 1882 Liberty Seated halves were struck at the Philadelphia Mint and have no mintmarks.
Check the back of the coin under the eagle to see if it has a mintmark, it can only be an O, S or CC, it may not have a mintmark but it makes a difference in value. Post new question with new info.
A Trade Dollar is a little less than an ounce 0.960157