A sham marriage (get a prenup if you want) is sufficient to have parents' income not counted by FAFSA.
Another way to save money is to rent an apartment and make that your permanent address freshman year than to pay out of state tuition and room and board. I always thought this scheme could never work until I met someone who played it and saved tens of thousands in the process.
If true, this is wild. I've never heard of it, nor of anyone exploiting it.