Just 2 quick questions.
As a senior I am entitled to the 7.50 ticket at the Prado, but do not see it on line. So, only can buy at window? Does the Prado sell out of tickets? Should I wait or pay the full price?
Second, how much time do I need for a taxi trip from Puerta de Sol to the Terminal 4 for a flight at 11:35, on a Saturday?
With the possible exception of special (temporary) exhibitions, I don't think the Prado sells timed tickets. It may limit how many tickets it makes available for free-entry periods as well as for temporary exhibitions, but I've seen no suggestion that tickets to the museum otherwise sell out. When people buy tickets in advance, it is usually in order to avoid spending much/any time in a ticket-purchase line. I did not encounter significant ticket lines on my two visits in May 2016, but others have reported encountering lines long enough that a tourist would want to avoid them.
The Prado website lists Reduced Tickets at 7.50 euros. Select your date, then click Continue, and you should see the option you're looking for.
