Having exhibited at juried arts & crafts shows for over 20 years, I've seen sales up and down. Some great, some pretty bad, but overall decent. I don't think the "economy" here in the US is that detrimental to sales. Most shows still have great turn-outs of patrons. People are there, most with wallets. If you've got images that grab people, at reasonable prices, you will do well. Problem is there are a gazillion people with cameras now. Competition is much higher for better shows than it use to be, especially with the advent of Zapplication. At a better show, you might have 50+ photographers applying for 10-15 spots. Photography has been the Number 2 medium at shows, shadowed only by jewelry. And to compound issues, what jurors usually want to see in jury images is not what the public wants to buy. This has long been a conundrum. In a nutshell, jurors want "artsy," cutting-edge images. The public often wants something that looks good over the proverbial couch. One thing for sure though, you cannot predict what the patrons at a show will like or dislike. All you can do is produce the best images possible, run them up the flagpole, and see who salutes.
Most photographers come with a variety of sizes and prices. Loose prints and ready-to-hang pieces.
A major problem that newcomers often overlook is the initial expense of doing a show. You need your own 10'x10' tent. $800+ for most. Display walls - The industry standard today are Pro Panels. A set of these can run $1000-$3000. Add browsing bins, office supplies, and lots of stock. Then there's the cost of the show. Most decent shows have a non-refundable application fee of $20-$35. Then there's the booth fees, which can run the gamut from $100 upwards to $2000+. My cheapest show is $150, and my most expensive one is $750. This gets you 100 sq ft of real estate (10'x10'). And unless it's a local show, add in travel expenses for gas and motel.
Oh!...and one other thing - you need a vehicle big enough to transport your tent, display, and stock.