The Early Spring 2004 Daedalus Books Catalogue has _Dear Bunnu, DEar Volodya. The Nabokov-Wilson Letters 1940-1971_ ed. Simon Karlinsky at $4.98. This is the revised edition with 59 new letters. Order#33927. Call 1-800-395-2665 or check web page.
 
An essential item for the VN scholar and dirt cheap.