Companies that are introducing a new line of goods during trade shows often bring items from older lines with them. This helps them to fill out their booth. It also ensures they will be able to show customers they have more goods to sell. Many times, new lines are either not for sale or are sold at full retail prices. This is not always true for established products the company has. These are often sold at prices slightly lower than retail.
The reason many companies do this is to clear out older inventory. Some also use it as a way to defray the costs of attending trade shows. Rather than lose profits when items are no longer popular, a company takes a chance that people would rather get an older design for less money. This has long been a good deal for companies that invest in trade show attendance.
Attending trade shows as a group is another way to get good prices. Vendors at trade shows are often willing to give larger discounts when multiple items are purchased. A group of people should get together before the show and discuss the items they want to buy. Once they agree, they can then plan to be together when shopping for items that can be bought from one vendor rather than several.
End of show discounts are not always available. Vendors that run out of items generally have to pay to have them shipped from their warehouse to the next show location. If they don't sell at one show on the tour, they can generally sell an item at the next show. End of tour discounts are often worth the wait, but buyers are taking a chance because the vendor may not have their item in stock by the end of the tour.