Sorry, but no. The author should never buy copies of their book to send to reviewers.
Again, it's the publisher's job to send review copies, not the author's. This is yet another example of the money flowing the wrong way. A memoir author who posts a review of another book (and, yanno, most other authors don't even post reviews) isn't likely to generate enough extra sales to justify the author's expense.
Joining forums for the purpose of promoting your own book is a Really Bad Idea. Joining them because one wants to be a member is fine, and there might be occasional opportunities to mention your book. But most forums (including AW, actually) have strict rules regarding self-promotion. People don't join forums to have stuff sold to them.