After an initial run on the Mint for the limited edition First Spouse 1/2 ounce
coins, interest seems to have waned as the price of gold (and the Mint's
ludicrous markup) increased.
Checking the Mint web site, I notice that a BU Buchanan's Liberty is still
available.
The "Liberty" coins may prove to be the most popular sub-set of the series but
at $800+ a pop, the First Spouse series ingeneral is rapidly losing any consumer
appeal.