I've seen it in Magalluf for as low as 5 euros a jug, but there's Sangria, and then there's Sangria.
This isn't an advert for our bar, but in our Jug we put a sangria mix, then add Brandy, Bacardi, lemon cointreau, Orange Cointreau, fresh orange, Red Wine, White wine and a mix of fizzy orange and lemonade, topped with fresh fruit etc.
I've known bars who put in the sangria mix, then add Orange and Lemonade and serve like that, with nearly a jug full of ice.
As I say - there's Sangria and then there's sangria.