Sorry, Larry, but offering 2 credits is not allowed. Many of these books seem to be wish listed.
From the red sticky thread on how to use this forum:
4) No asking (or offering) more than "PBS price" for a book. For example, "I will pay 3 credits for this Wish List book" is a violation of this rule, as is "I will send you this book for 3 credits" if the book is worth only one credit on PBS. All bound books "cost" 1 credit each at PBS, and audiobooks "cost" 2 credits each. We don't want a "bidding war" for books, and it is not fair to cut in front of members who may have been waiting for a Wish List book for a long time. That is why offering/asking extra credits is not permitted.