Ugh, tell me about it! For months, I've been watching Delta airfares for my April trip go up and down and up and down and up and down... Last week, they were really good, but I just couldn't bring myself to commit. Then early this week, they started inching back up, but not too bad... Then overnight they went up about $40 (making them $75 more than the lowest price last week) Not as bad as the OP's situation, but... OK, so now it has inched back down a little, not as good as it was, but better than yesterday, and still within my target range.
I swear, if the price is decent at all this weekend, I'm just going to do it. I always feel like the plane ticket is the one thing I can't change or cancel without a huge hassle and expense. And yes, I know Southwest is the awesomest awesome thing ever, but they don't have good schedules/options from my airport. Delta has far and away the best schedule options and the prices really have been pretty reasonable.
That's the one thing I don't love about planning a WDW trip, playing the airfare game.