While I respond to your point within my answer, I'm going to explain the whole question for anyone reading this later:
The argument concludes that one should never acquire expensive new tastes because they're pricey and because while you're acquiring these new tastes, you may run into things you find gross. The author adds in one last point - that the effort it takes to acquire new expensive tastes shows that those tastes are excessive (apparently reinforcing the fact that the tastes are too pricey).
Since this is a flaw question, we should try to identify some other gaps. I see one between each of the premises and the conclusion: Who says that you should not do things that burden your purse - or excessively expensive things as the final sentence suggests? And who says it's bad to experience gross things? The assumptions, that's who!
The answer, however, plays on a different issue. Are there perhaps not some benefits to acquiring expensive tastes that outweighs the costs? (E) notes that the argument fails to consider that acquiring an expensive taste might actually lead to some benefit.
(A) is tempting because the last sentence repeats an earlier premise. However, the conclusion - that it's unwise to acquire expensive new tastes - is not repeated. For an argument to do what (A) suggests, it would have to sound like: It's unwise to acquire expensive new tastes because among the many possible acquisitions, it is one of those that are unwise. Rather silly sounding!
(B) is out of scope - irresponsibility?
(C) is perhaps tempting - the argument does not define "sensations," however why does it need to define that term? Should an argument have to define every term it employs? And is the word "sensations" actually vague?
(D) is complex - if you struggle to read these correctly, when facing statements such as "mistakes X for Y", think of "The man who mistook his wife for a hat." Clearly the "thing" is actually a wife. In this answer, the thing that is treated as an effect is supposed to actually a cause for the acquisition - but how is being pricey or putting one in danger of experiencing unwanted sensations cause one to acquire something?
#officialexplanation