How to get from Madrid to Barcelona cheaply?

Personally, I think air tickets from Barcelona to Madrid are often very cheap, such as VUEling or Iberia Airlines. I bought a pre-tax ticket from Iberia 19 euros, and finally I added a booking fee of about 40 euros, which is cheaper than the train. The key is to be quick.

Air tickets from Madrid to Barcelona seem expensive. Maybe I picked the wrong time. There will be no tickets for the night train soon. Remind lz to book tickets early if I decide to take the train. On the other hand, the train is very comfortable and the seats are very spacious and stable.

I've never been in a car, but flying is very fast.