A 2-1 buydown lowers your rate by 2 points the first year and 1 point the second, then returns to the note rate. See each payment and the upfront cost.
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Buydown cost
Total buydown cost
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A temporary buydown is funded upfront (often by a seller or builder) and equals the payment savings in years one and two. After that, the payment jumps to the full note-rate amount, so make sure you can afford the final payment. It differs from paying points, which lowers the rate permanently.