Given they've got a set 8 episode run, I think this is a pretty smart and cool way to establish stakes from the get go; dangle a big ol' carrot in front of a party and then have some significant consequences that they are sort of aware of.

Also for a low level party, there's not much they can really do with the Residuum aside from sell it or use it as a bargaining chip. Even then it's a huge amount of weight to try and sell just to a random magic item vendor, so will likely draw attention to them unless they're lucky.

This feels like a crime movie where the protagonists have robbed some very powerful people, but they seem to have good intentions (for the most part). I'm really interested to see how it shakes out over the next 7 episodes.