How much is the Detroit Institute of the Arts worth? That’s one of the battles brewing in the Detroit bankruptcy litigation as a creditor tries to challenge the grand bargain reached that will wipe out $7 billion in debt for the city.

The key question is whether the grand bargain — $815 million pledged by foundations, state government and the DIA to bolster city pensions and shield the art from sale by transferring ownership of the museum to an independent nonprofit — represents a reasonable proxy for the value of the collection in the overall context of the city’s plan.

The other side is claiming the art can be worth up to $8 billion if sold off. The drama here is pretty interesting and the case could have interesting implications for the rights of creditors in bankruptcy.