Exactly the same happened to us. It is a dilemma. TBH I don't think anyone knows how these things work. Supply and demand, I guess. Some companies monitor how much interest there is online and put the prices up accordingly. Our holiday went up £200 in 24 hours. Madness. We managed to book it a bit cheaper through telextext but I kept checking website afterwards and noticed the price went up and up. As it turned out it was with XL so the flipping holiday got cancelled anyway!!