Cheap Tickets

I'm going to Minneapolis in February - that is, if I can find cheap airline tickets. I'm not going to Minneapolis for pleasure - there's nothing pleasurable about Minneapolis in the dead of winter. (I know - I used to live there). I'm going for my business, and thankfully there's someone else going with me. The problem is that I'm having hard time finding cheap enough tickets. I don't understand how you can fly from Maine to California for half the price of flying from Maine to Minnesota. Don't they realize that it's half the distance, so it should be half the price!?! I've flown from Maine to Michigan for $130. I've flown from Maine to Guatemala for $500. I've flown from NH to California for $200. So I really don't get how flying from Maine to Minnesota should cost $400!

Anyway, I'll probably end up going and just writing it off as a business expense (which it is). But I just would like to find a way to get there for a decent price. I'm open to suggestions!