Price-Compare Websites
These type of websites offer a wide variety of both new and used merchandise, many times priced much lower than the original retail cost. Websites like Amazon.com and Buy.com offer nearly every game made by the Big Fish company, available both new and used. Prices are so far discounted that you can most often find a brand new, unused game at a price you can afford.
Online Auction Websites
Online auction websites like eBay.com allow you to purchase items that other gamers across the world want to sell. When someone has a used Big Fish game, they list it on eBay.com, name their set selling price, or allow an auction to run for a set number of days, creating an auction environment where other buyers can bid on the item. If you have the high bid, you win the item, pay the seller, and receive the item by mail.
Video Game Stores
Most video game stores carry both new and used items, for both game consoles and PC. Large store chains like EBGames and GameStop both allow you to shop for used games both in-store, and online (EBGames.com, GameStop.com). When a fellow gamer trades in their Big Fish game to one of these stores, they are paid for the game, and the store in turn puts a price tag on the used game, offering it to you for a discounted price. You typically have better luck finding these used items in-store, as their websites are not always updated as quickly as used games come and go.