I see this sort of thing all the time. Mostly the rewards are a few hundred credits and the fine for non-delivery being 10-20K depending on commodity. ATM branching missions are just a nuisance, especially when you are hunting USS's for assassination missions. When working on my rep, I like to mix things up a bit.
'Abandon' missions should pay FINE+ORIGINAL REWARD+BONUS, or should be a 'threat' with a price being put on your head.