One thing to note is that no cards have mentioned whether or not they would be useful in the next event.
Ferrous Hero Iron Man
Ferrous Hero Iron Man is a pretty solid SSR for people who are just starting into SSR on their decks, but substantially inferior to many other SSR. Because of his mammoth versatility his buff is substantially weaker than other cards. His final stats are predicted to be around 10700 attack and 10300 defense, making him a jack of all trades card. But, with the increasing popularity of Tactics cards in the game I wouldn't be surprised to see him going for 20PP.
Ability Boom ISO-8s
Rewards for top level players in addition to the Iron Man card these are the true reward for participating in the event. Ability Booms have traditionally sold for a steady 30PP each. Recently I've seen them going for as low as 25PP each in my trade chats. I assume they will drop and remain at 25PP for sometime, especially now that many high level players have skill 10d most of their cards already.
Mutant Hunter Sentinel
A solid SR offensive wing card Mutant Hunter Sentinal offers a nice boost to its own attack for a bruiser deck. There is always a possibility despite it not being mentioned that Sentinel can be used in the next raid event. I don't find it likely, but hold onto it until you know for sure. If it is usable in the next raid event, you will probably be able to sell it for 10-15PP each.
Fickle Fortune Black Cat
Did we really need another Black Cat card? Oh well. Much like Sentinel, if it's usable in the next event it will have SOME value. If it's not usable in the next event it will be a nice addition to some lowbies deck since it is a degrade to all ability.