Well, I gave this a try last night, and heck it really does work. (At first I didn't realise it required secure storage and thought I'd been trolled!So just pick the palladium mission, take all cargo, and then sell it into your secure storage on your carrier (all). As a last step abandon the mission.
- If it was a wing mission and you picked all the cargo from the port then you won't get a fine, only lose a little reputation (what you can get back next time at the port after some credit donation missions).
- If it was not a wing delivery mission (or you don't pick all the palladiums up), you will l get the fine (= the price of the goods)
Next if you buy it back from your own secure storage it won't be flagged as stolen and it can be sold into normal markets - just like the CG.
Its a bit of a patience game to find these type of missions and you need luck, too, but the best sources of these missions are the refinery large pad ports with strong economy (high biowaste number) where the station owner faction is in Boom state.
FDev told earlier its not an exploit. But yes its a strange way / an alternative solution if resources are low (this method is first used by some Colonia players mostly for picking up tritium at the last Colonia Bridge station and then selling it to other players from their carriers).
However, I'm kinda confused about the whole penalty/fine policy. I mean, to get fined for taking some of it, but not get fined for taking all of it... where's the sense in that?
On my first mission I had space for it all, abandoned, no fine. On my second I ran out of space and thought "OK time to find out what happens if I don't take it all": LOL, biggest fine I've ever seen landed on my head - almost 280 million
I have to confess that it does feel seriously cheaty/exploity but if FD have denied this then... OK. (I do think they should at least fix the "no fine if you take it all" thing.)
I will probably get bored of unloading and park my carrier somewhere near the CG with cheap Palladium soon
[edit: will be interesting to see how long I can go without paying that fine - sadly it's with a faction I do actually trade with normally