Navigating the trade-in landscape comes down to your current monthly plan. If you already subscribe to an expensive top-tier unlimited package because of high hotspot data usage or international travel perks, utilizing a carrier trade-in promotion makes economic sense. You capture maximum residual value for an aging phone while absorbing zero additional service fees.
If you currently sit on a legacy low-cost plan or a lean prepaid tier, taking carrier bait is a losing mathematical proposition. The hundreds of dollars in extra service plan charges over 36 months will outweigh the equipment discount. In that scenario, pursue an unlocked trade-in appraisal directly through Apple, or sell your device on private marketplaces, purchase your upgrade outright, and preserve your low monthly expenses.