Ah, I get it.
You're a barman so you judge a city by the bar prices. If you do that, then yes, Paris is hideously expensive. However, having moved from London to Paris and taking a pay cut in the process, I had more disposable income in Paris than in London. Start with travel, then go to the cost of regular stuff like DVDs, games, CDs, supermarket shopping ... and as long as you don't compare bar prices, Paris is outright cheaper on everything.
So, if you're a tourist looking for a drink, sure, Paris is pricey, but if you're doing anything else, London is more expensive. Now you know why Parisians drink at each others' houses.