From the numbers you can tell I prioritize spending money on artists I like, hanging out, eating food, and staying close to the conventions. To make my profit margin stronger I should try to find someone to stay with when traveling or at least split a room(but I'm shy and lazy, bad combo), stop buying stuff at conventions(but everything is so cool), eat on the cheap and let my friends buy their own drinks and chow(also lame), focus on more finished art that can be produced as prints instead of doing sketchbooks(this cuts down on up front cost, and baggage weight, and also pulls in more dollars).
But I'm not serious enough about this. Conventions are basically hardworking vacations for me. I get to see buddies, discover new artists, meet people who enjoy what I do, and par-tay. With that mind set it is unlikely I will turn a profit in the years to come. But I know when I do get more serious about this stuff I know exactly what I need to do. There is some comfort in feeling that kind of sureness.
*note* The figures here aren't exact, because some dollars are spent in some categories and made in others because I didn't keep track, but I am pulling the numbers from my credit cards, cash, and square useage. It's close to accurate in amount.