The short answer
Calculate the complete device-and-service cost instead of judging a deal by its monthly credit or trade-in headline.
Step by step
Write down the retail device price, trade-in value, required plan, number of credit months, taxes, fees, and activation cost.
Confirm whether a new line, port-in, specific trade-in condition, or premium plan is required.
Compare the same phone bought unlocked with a lower-cost plan over the identical period.
Read return, restocking, shipping, and credit-start timing before ordering.
Save screenshots and receipts, then verify the trade-in and promotional credits on each bill.
Before you finish
Keep screenshots, receipts, chat transcripts, confirmation numbers, and the first bill after a change. Carrier terms and account eligibility can change, so verify the final price and conditions directly before submitting an order.