Re: To buy, or not to buy...Budo Renshu
Neither "Budo" nor "Budo Renshu" are really text heavy, so translation isn't much of an issue there (English translations of both books that I've seen seem, to me, to be accurate enough). The main attraction for those books are the drawings ("Budo Renshu") or the photographs ("Budo"). The approach to technique in "Budo Renshu" may not make much sense unless you have some familiarity with Daito-ryu.
There are two other books by Morihei Ueshiba, "Take Musu Aiki" and "Aikido Shinzui", which are both collections of essays published after his death. Although they are only available in Japanese, I found them quite a bit more interesting than either "Budo" or "Budo Renshu".