There are many places to list a GMC TopKick truck for sale including AutoTrader.com, Truckshopper.com and Cars.com. Websites like these specialize in car and truck sales, charging users a monthly fee to place an add on their site.
eBay Motors and craigslist.org both allow free listing of cars and trucks for sale. eBay charges a final value fee based on the final sale price. There are no fees to use craigslist.org to sell cars or trucks and is entirely managed by the user. GMC Topkick trucks can also be traded in or sold back to GM dealerships across the country.