Perfectly logical assessment, but it rests on the assumption of trust in the developer/publisher. Look at their word choice: "Deluxe" denotes the full game, while "Regular" is the cheaper version. If what you're saying is true and the intent is to offer a cheap alternative to a full price VN, wouldn't it make more sense for the full game to be "Regular," and the alternative be called "VN on a budget," or something along those lines? I admit I'm not very familiar with VN pricing, but have CG galleries and voiceovers really been considered "deluxe" in the past? I won't accuse Frontwing of anything devious, but cutting content out of a game and offering it as DLC is always dicey. Even if they do it right, it sets a precedent.
In any case, having already played Sharin I'm relatively indifferent. Guess it couldn't hurt to throw a few bucks their way, though.