You will find an abundance of Oriental vendors with wives and even babies. There, sub-teen children are enlisted to bring additional merchandise in from the vans as the tables get depleted. You will find little in the way of used merchandise although there is generally one vendor selling used and refurbished computers at rock bottom prices. To do some intelligent purchasing, you will need to know what regular prices are. I have never purchased a full computer at a show, but they are available there and being demonstrated.
Savings can be very substantial.
I get a little uneasy however when the vendors open the machines right on the spot to show off their innards, or to change chips. One area with outstanding prices was in small peripherals. More normal cables were generally one third to one fifth of the price of those sold in discount stores. Many books were on display, at good discounts. There is a lot of software, one version older than the latest one, available at bargain prices.