Refinance Breakeven Skill

"Lower monthly payment" and "saves money" are different claims, and lenders profit from the confusion. This skill computes when a refinance genuinely breaks even — and names the two standard ways the simple math lies: the term reset that trades a lower payment for more total interest, and the cash-out that relabels borrowing as saving.

What This Skill Produces

• The breakeven analysis — payment delta, upfront costs, the month cumulative savings pass them
• Both interest totals — keep vs refi, side by side, costs included
• The honest verdict — refinance / don't / refinance-but-shorter-term, with the reason

Required Inputs

Ask for these if not provided:

• Current loan: remaining balance, rate, months left
• The offer: rate, term, closing costs, points (if any)
• The horizon: how long the user realistically expects to keep this home/loan — breakeven beyond the horizon is a loss dressed as a saving
• Cash-out? — if the refi increases the balance, say so; the analysis changes character

Programmatic Helper

python3 scripts/refinance_breakeven.py --balance 380000 --rate 6.9 --months-left 336 \
    --new-rate 5.6 --new-term 360 --closing 6500
python3 scripts/refinance_breakeven.py --json-input refi.json --json

Standard amortization, simple-savings breakeven (cumulative payment delta vs upfront costs). The script prints the term-reset warning itself when the new term extends the payoff date. Not modeled — and say so: reinvestment of savings, tax deductibility, ARM resets.

Framework: When Breakeven Math Lies

The lie	The tell	The honest comparison
Term reset	26 years left → "new 30-year loan"	Total interest both paths (the script prints it) — or price the refi at the same remaining term
Cash-out gravity