As I promise here comes the 'tapas' route:
Every Thursday, between 19-23 h, you should go to Poble-sec (a really nice Barcelona's neighborhood). A bunch of restaurants offered one 'tapa' and a beer for just 2 €. 17 bars are subscribed, such as La Soleá, la Saltó, bar Rufián, taverna Koska, Patán, etc. Plus, the 10% income of every first Thursday goes to a neighborhood' s ONG.
We went to la Boheme, Patán and Blai tonight (not subscribed)
A friendly bar without wifi. We ate montadito de crema de puerro (leek cream)
We had a tapa of salad with tuna, caper and black olives. Then out out the special Thursday offer we had a extremely delicious croquetas de chorizo picante de León (croquette of highly spiced pork sausage).
This bar is not subscribed to the Thursday' offer. But u can have any tapa u see for just one €. I had, in order of appearance, cranc gamba i caviar (crab, prawn and caviar), tomato and brie, patata pochada con uevo y pimento verde (cooked potato with egg and green pepper) which I highly recommend
The special offer of Thursdays nights is not so special. All the tapas of that offer are made from vegetables. My opinion is that u can eat some tapas of that offer and later go to Blai tonight, but don't expect a really tasty 'tapas' for a reasonable price of 1 €
It's a good choice if u wanna have a bunch of tapas for a really cheap price.