Not-so-homemade sangria
There’s an unwritten rule about restaurants selling premade food and drink: don’t do it. However, there’s another unwritten rule only restauranteurs know about: if it can save you money, ignore the previous rule. That’s exactly what the OP’s bar did with sangrias.
We’ll be the first to say that there’s absolutely nothing wrong with selling wine in a box, provided that the company is transparent about it. But for obvious reasons, they’re not, and they’re overcharging you a premade cocktail. Will this stop customers from downing glass after glass of sangria? Probably not, and that’s exactly what the bar wants. All hail the mighty dollar!