Grab an inexpensive hotel for the night, right by the outlet so you can save your money for shopping, and then spend a day or two browsing the shops. No need to go out to an expensive meal, instead have everyone chip in for one of the meals and bring a different type of cheeses, meats, and crackers and head poolside for an old-fashioned wine and cheese get-together before or after the shopping trip.
Since this is a budget trip, consider to following:
*Setting a limit to spend that is comfortable for all, and make it a game in which no one can go over budget. This also helps with those that feel that shopping is a competitive sport.
*Set a prize for the person who purchases the best sale priced item.
*Include getting a picture, if possible, of the most hideous item found on sale and vote on it later by the pool.
*If it is a gift-shopping adventure, give a prize to whoever ticks off the most people on their list.