I kind of just evaluate how much I want the tournament dragon. If I really want it, I am willing to budget some gold to get past the toughest opponents. I try to take them down, but if I don't succeed after 4 or 5 tries, I just use gold and move on. I figure, "If this dragon were in the marketplace, how much gold would I be willing to pay to buy it?" I realize that buying gold is not an option for everyone. I usually hate to spend more than 120 gems per dragon, so that is 4 rounds I can "skip" if I really want the dragon. I also factor in if it is going to help me with a bingo task. Like, if a bingo task comes up to win a battle with a particular type of dragon, and I am up against something like Battlemage, I will just go in knowing I plan to use gold to get past that round and complete my bingo task.
So Battlemage is a tough opponent, and I like his looks. I am planning to craft one as soon as I get my Essence built up again. Is he a good fighter on our end, or is he just a good fighter as an opponent?