What is the value of an 1887 US 1 dollar gold piece?

In circulated condition this coin's value is mostly determined by the fact that it's made of a 90% gold alloy.

Numismedia lists the following approximate retail values as of 04/2010:

Very worn condition - $126

Moderately worn - $162

Slightly worn - $214

Almost no wear - $306

Uncirculated - $460 to $13,980 depending on quality