Mountain Dew fans looking for hard-to-find flavors have several releases to watch this fall. The latest buzz includes the return of the Mountain Dew Trolli Cherry Lemon Froster at Circle K, the exclusive Blackberry Citrus soda at Casey’s, and the limited-time Mango Pineapple Punch collaboration with Trolli. Each has a different availability story, which matters if you are trying to find a bottle without paying collector prices. Some releases are sold through regular retail channels, while others are restricted to a particular convenience-store chain or format. Before buying from a reseller, it is worth checking whether the flavor is still available at its original retail price.