what about some pasta and some nice tomato sauce (or ketchup if you are really low on money)or perhaps some rice with chicken?

You could buy some meat (anyone you want) that goes well with both rice, pasta and potatoes, that way you can make a basic "stew" and one of the three suggestions and then you can eat the "leftovers" next day with one of the other three suggestions. That way it´s both cheap and with a bit of variation...