I haven't really heard of those too much. If I were you, and I'm not... But if I was I would save your money, and build it up so you could make a really awesome costume for Anime USA or katsucon. Otakon is coming up rather soonish, in july I believe, but It kinda... it didn't wow me. But it's a great place to show off your costume. Out of all of those, however, I would have to say Nebraskon. I had a friend that went and had some pretty good fun there. But I would wait until AUSA. I regretted not going so much this year.... I had such great fun last time I went :/