I’ve been working awfully hard to complete my Usagi Yojimbo TPB collection over the past year or so and I’m happy to report that after receiving Book 9: Daisho, Book 14: Demon Mask and Book 15: Grasscutter II a few weeks ago (that last one was a real bugger until recently!) that my TPB collection is finally completely up to date. Whew, what a journey!
And as a way of helping anyone still working on their own collection, let me recommend using online retailers like amazon.com that offer discounts on both new and old books alike. 
But for those harder to find books and a more personal touch, please consider using Heritage Source, a book retailer specializing in Japanese-centric English titles and a good friend to Stan Sakai. Carolyn there was able to help me find two of the harder to find collections for cover price (when they were going for far more) and went out of her way to keep me informed of when they were available, discussed the order with me personally and was as kind as she could be, shipped quickly and all the great things a good business should do. Seldom do I see that kind of attention to customer service these days and if you value that Heritage Source might be a book source worth looking into.
