I think someone's trying to keep these flights secret! The Manchester Airport website doesn't list Minorca among its destinations and the Menorca Airport website doesn't list Manchester!! Despite this, a quick visit to the Fly Monarch website suggests that you can get scheduled flights for �35 - �40 each way. (You might find them cheaper. I just tried a couple of random dates in May): http://www.flymonarch.com/
try www.jet2.com, ive flew with them before and there good. i dont no if they will beany help to you but its worth a try! or u cud try easy jet or bmi baby, although a friend had a bad experience with bmi!