I haven't been to Ushicon, but I've been up the 
road at A-kon for the last three years. ;o)

As far as my (very limited) experience goes, 
there are usually a handful of cel dealers--- but 
they tend to have a few cels in the mega-pricey 
range (ie, big, winged Van's, etc, selling for 
four-digit), a lot of cels in the junky range 
(itty bitty distance shots), and a lot of cels in 
the moderately-ehhh range. As far as prices go, 
better deals can definitely be found from fellow-
collectors and Ebay, but I guess there's 
something in the air at a convention that allows 
fans to pay "convention prices". ;o) As far as 
variety is concerned, you have a lot of 
Sailormoon, Dragonball, and some other popular 
series... but if you're interested in something 
non-mainstream, let alone non-licensed, chances 
are pretty slim they'll have much of anything to 
choose from.

Last year, I was standing at a table hunting 
through a box of trading cards, and the next 
table over belonged to a cel vendor. The guy in 
charge of the table was chewing out his 
assistant... it seems the credit card machine was 
in another room, and he was angry that his 
assistant had allowed someone to use plastic on 
an item that was less than $100. It wasn't worth 
the walk otherwise, he said... I'm sure most 
vendors are very nice, but it made me rather glad 
I have an email barrier between me and my seller 
so I don't have to hear them gripe about how my 
collecting habit is peanuts. ;oP

-Cres