give them hell!!! a comic-con is as level a playing field as you can get...just rows of tables and it's yours vs there's. I've done hundreds of these. One thing I can tell you is to be outgoing. Be friendly, be proud of your work and the effort you put into it. Do not be shy or afraid to say hello to passers-by and ask them to check out your work, and do not be discouraged if they aren't interested, and don't make it awkward for them if they aren't..Just thank them for looking and move onto the next person.
No matter how good you are, some people ain't going to like it. some people ain't going to have extra cash. That's the nature of the beast.
Just keep in mind, you're doing something none of them are or can do.
...they can't do what you do. If someone's looking and seems sorta of interested, introduce yourself, explain how you did it, why you picked that subject, ect.
btw, I like the Daredevil and Electra and Cthulu vs Dr.Fate the best!