From the beginning Band of Misfits is a card that I have never completely obtained a solid grasp of, but I recently played a game--wish I would have grabbed the log--in which it was extremely useful, especially with two cards: Tournament and Coppersmith.
On a board that had: Crossroads, Swindler, Urchin, Coppersmith, Tournament, Trader, Silk Road, Band of Misfits, Boarder Village and one other card I opened 5/2.
I quickly realized that Band of Misfits would be a key card in allowing me to use it as coppersmith in hands were I had 3 or 4 copper to quickly get up to 6 or 8. Using it I scored an early gold and an early province leading me to obtain 3/5 of the Prizes. I was able to use BOM as Tournament later in the game when I had a province in hand. I think I only bought 1 Tournament, which was nice because using BOM I didn't have to worry about it being a dud against another player's revealed Province.