Does that supermarket have a store in your university town? Might be worth asking for a transfer...
Personally, I would say that committing to going home every weekend would be a mistake. The weekend is a great time for socialising, if you join any university societies they'll often organise weekend things, my uni even has lectures on the weekend - so you really want the flexibility to stay at uni if you want to. Particularly in your first year, which is the time to try out new activities, make friends, etc. - which would be hard if you have to spend every evening all week studying in order to be able to take the weekends off, then disappear away home for the weekend.