What is the real cost of giving up your rate?
This is the variable everyone leads with, so let me address it directly. If you locked in at 2.875% or 3.25% during the 2020 to 2022 window, that rate is a financial asset. It is not pretend. On a $400,000 balance, the difference between 3% and today's rates can be $1,200 to $1,800 a month in interest alone. Over ten years, that is real money, and any honest agent should say so out loud.
But the rate is not the whole monthly payment, and it is not the whole decision. Here is the question that actually matters: when you apply your existing equity as a large down payment on the next house, what does the new monthly payment look like, and how does it compare to what you are paying today? A $250,000 equity check applied to a $650,000 home means you are financing $400,000, not $650,000. The rate is higher, but the principal is smaller. The blended monthly cost is usually closer than people expect.
Run the math, then make a peace-of-mind call about what the gap is worth. If the new payment is $400 a month higher and the next house solves three real problems, that is a defensible trade. If it is $1,500 a month higher and the new house solves one cosmetic problem, that is not.
Tool for this variable
Buy-Before-You-Sell calculator