Just watching Birmingham in the Europa League, probably going out. The predicted earnings aren't high even if you win it, unlikely when teams drop down from the Champions' League (that's another debate). Birmingham haven't done badly, but has their qualification injured their promotion chances. Getting into PL is worth far more surely.
Got some good players there, but can they say 'no' to a few million in January, thats the question. If Chris can keep that squad together, they will be up there at the end.
At the end of the day, football isn't about money, it's about winning trophies. The only purpose of money in the game is to fund a team that is good enough to win trophies. Therefore winning a tournament should always be top priority. In Birmingham's case, maybe it is more important to just try and get promoted, and I don't think that clubs outside of the top divisions should be able to play in European competition. However, for the top-division clubs in the competition, it definitely is worth it. It's what all fans of football dream of experiencing. If the game was just a perennial quest to earn as much money as possible, then it would be pointless.
A european tournament is worth it as gremlin said - european stage/exposure/playing different teams/the excitement of playing in Europe. But NO, The Europa league format as it stands at the moment is rubbish - far too many games and the drop outs from champions league -all wrong