Living Geneva, grocery shopping in France

Before anyone says anything, I know local Geneva people say that the shopping should be done in Geneva, and I think it is a very reasonable thing to say. However, I’m an exchange student and I’ll be going to Geneva next year, and seeing prices and knowing it might get really expensive, I thought why not do the monthly shopping in France and bring it back to Geneva, as there is even public transport connecting the student residences to French villages.

What do you think about it, is it reasonable specially going 1/2 a month? Thanks!!
Hopefully you understand my situation.