In the end, weighing pros and cons - and admitting a certain dose of curiosity - I opted for the national airline of the country I was going to visit. Given that my ticket was only one way, and that the airlines do not like, I knew that my credit card was going to shake and, indeed, 387 euros in total came out to pay for the trip. And that I did not even suspect my problem with the visa for Uzbekistan which meant, among other things, to spend 50 euros to change the date of the flight.
To travel to Barajas the most convenient thing was to use the Metro. Since the EMT guarantees the opening of stations until 01:30 am, it had to be before that time in Nuevos Ministerios, beginning of line 8 leading to the airport. I did it without problems, and with enough time to compensate that at night the frequency of services is reduced.
this is not english