The same work goes into producing Cava, Woofie, produced under the description 'Méthode Champenoise', and that can still sell for a fiver a bottle. Big name, big price.
Some years back, Asda's own brand Cava was selling at something like £4.69 a bottle. Some days before Christmas, they reduced the price to £2.49 a bottle. Malcolm Gluck, wine critic for the 'Guardian', classed it as being superior to Krug champagne, which was selling then for £100 a bottle. Tells you something.