I'd make it 100% clear in the contract what you are expected to give out as artwork, whether it's files with styles, layers, flattened files with no layers or styles, InDesign files and/or Print Ready PDF/Web Ready PDF or both; etc.
Pet Hate
I particualarly hate getting InDesign files, that I paid a designer to do, that have no paragraph or character styles or other things. I've had it out with them too! My point of view is that I state I want editable files for InDesign, and I expect that to include all the styles. I lose faith in any designer who supplies a file without proper layers or styles. In so much that I've actually stopped using their services. The whole idea of me paying someone else is to make my life easier when things are on a tight deadline. And getting files that are stripped of styles drives me bezerk!
So on one hand you may not get the programme again. But on the other the people hiring you might lose faith in your ability to use InDesign if you don't supply styles.