Graig,
I have attended two National Conventions. While I have gone there with a specific plan as to what to purchase, I have also found that i have saved and purchased items from vendors sometimes months after I met them at the show. From that standpoint, I feel that going to a future National will be very beneficial to you and I really hope that you go to next year's National in Chicago so I can meet you!
Your paintings speak for themselves and will attract people to your booth. Personally, if you sell some 5x7's I know that I would purchase a couple. You are a very talented artist! Keep doing what you are doing and you will gain even more notoriety. That happened to a friend of my family who was able to attain a very high degree of acclaim.
Best of luck to you and I will say this again. Please go to the National in Chicago next year!