Regarding [the plan] to collect my writings in volumes, I am quite cool and not at all eager about it because, roused by a Saturnian hunger, I would rather see them all devoured. For I acknowledge none of them to be really a book of mine, except perhaps the one On the Bound Will and the Catechism. (LW 50:172-173)
If anybody wishes to become a theologian, he has a great advantage, first of all, in having the Bible. This is now so clear that he can read it without any trouble. Afterward he should read Philip’s Loci Communes. This he should read diligently and well, until he has its contents fixed in his head. If he has these two he is a theologian, and neither the devil nor a heretic can shake him. The whole of theology is open to him, and afterward he can read whatever he wishes for edification. If he wishes, he can read, in addition, Melanchthon’s Romans71 and my Galatians and Deuteronomy. These will give him the art of speaking and a copious vocabulary. “There’s no book under the sun in which the whole of theology is so compactly presented as in the Loci Communes. If you read all the fathers and sententiaries you have nothing. No better book has been written after the Holy Scriptures than Philip’s. He expresses himself more concisely than I do when he argues and instructs. I’m garrulous and more rhetorical. “If my advice were taken, only the books of mine that contain doctrine would be printed, such as my Galatians, Deuteronomy, and John. The rest [of my books] should be read merely for the history, in order to see how it all began, for it was not so easy at first as it is now.” (LW 54:439-440 Tabletalk)
Indeed, you say so much less, and attribute so much more to free choice than the Sophists have hitherto done (a point on which I shall have more to say later) that it really seemed superfluous to answer the arguments you use. They have been refuted already so often by me, and beaten down and completely pulverized in Philip Melanchthon’s Commonplaces—an unanswerable little book which in my judgment deserves not only to be immortalized but even canonized. Compared with it, your book struck me as so cheap and paltry that I felt profoundly sorry for you, defiling as you were your very elegant and ingenious style with such trash, and quite disgusted at the utterly unworthy matter that was being conveyed in such rich ornaments of eloquence, like refuse or ordure being carried in gold and silver vases. (LW 33:16)
Luther praised the fables of Aesop highly: “They are worthy of translation and of being put into a proper order and arrangement. It is not a book that was written by one man only, but it was diligently assembled by many men in different centuries. It would be very useful therefore if somebody would translate the book well and put it into proper order. The important fables that are pithy, smack of antiquity, and are useful to the commonwealth ought to be gathered into a first book; then those that are more elegant ought to be placed apart in a second book, and the rest ought to be reserved for a third. “It is a result of God’s providence that the writings of Cato and Aesop have remained in the schools, for both are significant books. Cato contains the most useful sayings and precepts. Aesop contains the most delightful stories and descriptions. Moral teachings, if offered to young people, will contribute much to their edification. In short, next to the Bible the writings of Cato and Aesop are in my opinion the best, better than the mangled utterances of all the philosophers and jurists, just as Donatus is the best grammarian.” (LW 54:210-211, Tabletalk)
While all these are interesting to see what Luther valued (there are probably more comments like this), this comment was not referenced by the blog post, and I think it's the most telling. Looking over his life's work, Luther said:
“I would have been quite content to see my books, one and all, remain in obscurity and go by the board. Among other reasons, I shudder to think of the example I am giving, for I am well aware how little the church has been profited since they have begun to collect many books and large libraries, in addition to and besides the Holy Scriptures, and especially since they have stored up, without discrimination, all sorts of writings by the church fathers, the councils, and teachers. Through this practice not only is precious time lost, which could be used for studying the Scriptures, but in the end the pure knowledge of the divine Word is also lost, so that the Bible lies forgotten in the dust under the bench (as happened to the book of Deuteronomy, in the time of the kings of Judah)…
I cannot, however, prevent them from wanting to collect and publish my works through the press (small honor to me), although it is not my will. I have no choice but to let them risk the labor and the expense of this project. My consolation is that, in time, my books will lie forgotten in the dust anyhow, especially if I (by God’s grace) have written anything good. Non ere melior Patribus meis. He who comes second should indeed be the first one forgotten. Inasmuch as they have been capable of leaving the Bible itself lying under the bench, and have also forgotten the fathers and the councils—the better ones all the faster—accordingly there is a good hope, once the overzealousness of this time has abeted, that my books also will not last long. There is especially good hope of this, since it has begun to rain and snow books and teachers, many of which already lie there forgotten and moldering. Even their names are not remembered any more, despite their confident hope that they would eternally be on sale in the market and rule churches.” (LW 34:283-284).