Another recommended buy is ready-made Spanish Omelette (aka Tortilla) - think that was around £2.50, weight not given in the ad. But they are so easy to make and again, much cheaper to do it yourself (less than £1 I would think).
Spanish Omelette: serves four - six
1 lb waxy potatoes, unpeeled cut into small chunks
1 large Spanish onion, diced
4 - 6 eggs
seasoning to taste
oil for frying
In an omelette pan put in a little oil. Saute the onions and potatoes until the potatoes are just tender. Beat the eggs (one per person) and season to taste, pour this over the potatoes and onions and cook until just set. Slide the omelette onto a plate adding a little more oil if necessary to the pan, then tip the plate so that the uncooked side of the omelette falls downside onto the pan and continue to cook until golden underneath. Serve hot or cold in wedges. Alternatively, leave it in the pan and finish off under the grill.
This is the very basic recipe but gives plenty of scope to add other ingredients if you wish - peas, chopped peppers, sweetcorn - even chopped ham or chorizo. It's up to you.