It would be a pretty huge deal for the collector (s/he who will pay to the northern end of the range) given the matched serial plates. Getting one even with mismatched serials would be an additional expense worth considering.
Conversely pads would be of greater value to the listener rather than the collector (though I'm not sure whether the listener would pay more for pads or the collector for the matching box). At least the original pads don't suffer from serious issues like the HE60/HE90 pads that make replacement absolutely imperative; the main issue with Omega pads is that they become stiff. I believe at least one owner (Birgir?) has had success treating the original pads to make them a bit more supple, albeit nowhere near new.
We know HE90s are worth about 15k because they rot around if they list for much more. We know MDR-R10s are worth in the neighborhood of 5k because much more than that and the same phenomenon occurs. I actually haven't seen enough lasting listings of the Omega to affirm that position with such certainty -- they are much closer to the rarity of the HE90 than R10s, aren't priced out of accessibility like the HE90s, and the existence of the SR-009 makes them less interesting to people who just want sound without fuss.
I find the Sony stuff more rarer and harder to come by then the Stax, for instance Larry has reduced the population of the CD3k's because his butchered them all for wooden creations.
Collectors or listeners, it's hard to say which is more because I know some collectors on this board who are frequent listeners so it's hard to set apart the distinctive groups.
For me I'm bit of both but more so a listener, yes the original box is nice but I'd rather pads and headbands because they affect the functionality of the headphones, it's no good as a complete collectors item with the box and all If the pads or headband are completely mangled.