My new book is now in stock at Amazon as a paperback edition, if you are interested. I am pleased to see that it is already in the top 100 bridge books for current "sales rank!" The price at Amazon is $11.95, with free shipping available.
You can also find it at a discount at Barnes and Noble for $8.60 right now: http://www.barnesandnoble.com/w/overcalling-opponents-1nt-ken-rexford/1108315832?ean=9781554947621&itm=1&usri=overcalling+opponent%27s+1nt, but this might not include the free shipping.
If you get the book and enjoy it, please consider writing a review on these sites. If you hate the book, get around to a review later! ;-)