What is the value of an 1877 US trade dollar?

Check on the back to see if there's a small mint mark letter. Numismedia lists the following approximate retail values as of 02/2010:

No mint mark (Philadelphia):

Very worn condition - $86

Moderately worn - $144

Slightly worn - $162

Almost no wear - $365

Uncirculated - $1,020 to $26,880 depending on quality

"CC" mint mark (Carson City):

Very worn condition - $222

Moderately worn - $318

Slightly worn - $510

Almost no wear - $896

Uncirculated - $2,850 to $90,630

"S" mint mark (San Francisco):

Very worn condition - $84

Moderately worn - $144

Slightly worn - $174

Almost no wear - $358

Uncirculated - $1,020 to $56,250