I suspect that the score offered by Hoyt et al is the miniature score;
I don't think that full scores have been available for sale in many
years, if at all.

Hoyt's price is about the dollar equivalent of the sterling price offered
by the London branch of Boosey and Hawkes specifically for a miniature.

A shame Boosey hasn't brought it out in one of those relatively inexpensive
big paperbacks as they did "Concerto for Orchestra" and assorted Britten,
Bernstein, et al.

Best wishes--
Joel Lazar
Bethesda MD