That was a great opportunity for the buyer who found your auction amidst 1200+ other auctions. It will remain to be seen if the buyer takes the knowledge availed in the newsletters and introductory texts and continues their study. Will they be better informed and better appreciate what they study or will they be looking for the next bargain? Will the be ready for the next book in their study as a tool to advance their learning?
Many clients have told me that they will spend on books to save on costly mistakes when buying swords, tosogu, etc. Since 1999 I have sold a great many books to many advanced collectors. It was striking was to see how quickly they many advanced on the learning curve. It was not uncommon for someone to go from asking me what was the next book that they needed, to their asking me to obtain a book at their direction: collectors who would read through a bibliography to read source material and in some cases pay to have it translated. The other thing that impressed me over the years is the number of students who do not collect. As one person told me, they do not limit their taste to what they can afford and rather studied to appreciate the art.
To top it off, it kills me that eBay will also assess its fee against your shipping costs too. I hope the sale didn't need to go overseas.