The reasons why I listed this armor at the price it is listed are as follows:
1) This is the best armor available for pvp4 hunting unless you can afford Carramone, and can get Skalman to let go of it. The mulmun, muluk hir, and mulaak'f are pure impact, and the people who shoot you in the back while hunting them are usually pure burn and pen. These mobs drop fantastic MU, and having an armor set equipped for both PK and hunting them makes this a very valuable set.
2) The set is, of course, also a great PK armor on its own. It's like a slightly toned down UL version of infiltrator, except it provides electric protection instead of acid. With the new laserfaust guns on the market, that electric protection comes in handy.
3) It is true, I won't be hunting too many scips, spiders, or trox in this armor, but I can hunt big ambu, daspletor, big bulk, segs, sumima (even the big ones hit for super low damage), all burn/pen bots, steel birds, and even evisc (up to the medium ones). RX provides over 20 more impact protection than eon, and it makes a huge difference on those pure impact mobs like the bulk. Of the imp/stab/cut mobs, I can't think of one that gives me better MU than bulk, segs, or the pvp4 mutants.
Edit: For the record, while I choose to keep the final purchase price private, it was a good deal more than 28K.