Graig,
I agree with some of the other comments. I do think that is a combination of price point and desire, with the latter being more relevant. HOWEVER, I think the exposure acts as targeted advertising. I have been to several Nationals and many large regionals and each time I went with a budget and a wantlist. That is not to say I haven't purchased some things way off of my radar going in, but those items were in the minority. But the most important aspect that I think relates to you and your
(awesome!) work is I have seen items and made the purchases at a later date from vendors that I have met there that otherwise I would have never been exposed to (pre-internet).
While we at Net54 are all familiar (and covetous) of your pieces, someone viewing them for the first time may take a little time to justify/decide/budget for their purchase. This obviously doesn't bode well for the balance book at the end of the National, but I believe may pay off in spades for the future.
edited to add: What Scott said.