You have evidently forgotten that UCD is located in the centre of Dublin 4, so affordability is not easy to come by. Campus rents practically require your firstborn child as a deposit, so the €17 burger meal from Mikeys seems less bad in that light but still not great. Centra is about as affordable as Café en Seine, and the clubhouse “discount” feels much less discounted these days. There are, of course, bins and other sources of food that the abundance of rats and foxes live off; speaking of which, they too are a very affordable source of protein on campus.
Otherwise, though, you must just accept that the D4 life of poverty is not cheap.