Trade or not really does not matter.
Rents at the same place are the same (say $2000) or not does not matter.
The fact is:
You are consuming $2,000 for living at other people's place.
You are receiving $2,000 from other people who lives in your place.
Passing money/check or not does not matter.
Now, if you can prove the other person and you actually belong to the same family, things might be different.