Barcelona Card vs T-Casual for discountsThere are no discounts with the T-Casual. It is a transport only ticket. In summary for discounts: Barcelona Card gives you discounts on entrance fees for attractions, official Barcelona Turisme souvenirs shop, some restaurants and selected performances.
The Barcelona Card is a 3-in-1 transport card, museum pass and discount card. Holders of the Barcelona Card enjoy unlimited free travel by public transport, free entry to Barcelona´s best museums, 70+ deals and discounts on visits, tours, entertainment, shopping, dining and nightlife.
At each station of the metro and FGC, you can buy tickets either at ticket machines or ticket booths. The machines can also be operated in English. In the bus you can only buy single tickets from the driver. With the tickets bought on the bus you can change to other buses, but not to the metro.
A ticket valid for a single TMB bus journey. This is an individual non-integrated ticket. Single bus tickets are fully digital. You can purchase and validate them on the bus by contactless bank card (also mobile or smartwatch).
Cash vs. CardsYou will need some cash. Small businesses have credit/debit card minimums, especially at markets like La Boquería and Santa Caterina. Consider ordering some euros to pick up at your local branch before your trip.
So Is Sagrada Familia Worth It? All indication, as well as my own personal experience, points toward Sagrada Familia being an unforgettable experience. Whether religious or not, a visit to this Gaudian masterpiece tends to be a religious experience.