Air Kenya has cheap deals most of the time but I prefer to fly Air France or Air Mada (although they have dramatically cut their flights lately) Madagascar is not cheap unless you take a freighter. Expect to pay about 600-700 GBP if you get a good rate. If you go to volunteer sometimes they offer a discount for Air Madagascar from Paris. Madagascar is fantastic. Highly recommend.

Qatar airways to southafrica. Get a cheap fly to Soutafrica from London or Paris....and once there get another ticket with kulula.com to fly there. Thats the easiest way

Air Madagscar: from Milan to Antananarivo toe times a week on Saturday and Wednesday

cheapest would probably be to work your way off on a freighter out of hamburg or marseilles, though not much fun and might take a while to get there. also a bit more expensive would be to just book passage on one (cargo ships used to have room for a couple passangers - not sure if they still do that though), you wouldnt have to work, but you'd get bored to death

air corsair flies from paris orly to antananarivo and there are some cheaper ticket in september.

why would you want to go to madagascar? flight to south africa then kalola flight to madagascar

i think that the cheapest way to get there is with some low-budget airline company... or by boat...