I've looked over their resale policy, and it's restrictive and case-by-case, with $50 service pee (paid by the seller ahead of time, so it's a risk at my end), but I need to free up disc space and NEVER use these products and NEVER will.
Omnisphere is a bit iffy -- I've only used it three times and due to how much effort it takes to browse what it has to offer and to audition and compare, I tend to overlook it compared to having so many other choices for sound effects and ambient textures (the only two things I would ever turn to it for anyway).
But Trillian was a no-go from the outset; I bought it on someone else's advice. I despise it 100%. It is so well-loved and I'll never understand why. Maybe the synth bass stuff is good, but I have no need for that as I have a Moog Voyager.
Stylus RMX doesn't meet my workflow; I bought it on recommendation from others too, at a time when there was less out there. But I never use audio loops or related technology. I have a lot of packs bought cheap too, but I think they can't transfer to anyone else.
Be aware that only one resale is allowed, from the original owner. Rules are here:https://www.spectrasonics.net/support/knowledgebase_view_topic.php?id=273&categoryID=78
As with the other stuff, I'd only ask $10 above the transfer fee, for $60 total, just to cover any surprises in exchange rates, PayPal fees, etc.