What I like about it is he's back to being a bounty hunter and like in ESB he gets paid twice for the same job.
The exposition needn't be explicit, all we need to know is the Rebels have paid Fett for tracking the Emperor and finding the Death Star and Vader has paid him for making sure the Rebels arrive at the party on time (Dave just did it like that to get the idea across).
"I hope it's worth the price we paid" takes on a different meaning.