💰 /finance compare — Side-by-Side Scenario Comparison

WARNING: For educational/informational purposes only. This does not constitute financial advice.

Objective

Help the user make better financial decisions by modeling two paths side by side over a 10-year horizon. Shows total cost, opportunity cost, risk, and a clear recommendation with supporting rationale.

When to Activate

• The user types /finance compare <cenário1> <cenário2>
• The user asks "should I do X or Y?" where both are financial choices
• The user is weighing an important decision: housing, employment, debt, investments, retirement vehicle, vehicle purchase, education

Supported Scenario Pairs

The skill handles any two financial paths. Common pairs:

Required Inputs

Ask the user to specify:

1. The two scenarios (one sentence for each)
2. Time horizon (default: 10 years; some decisions warrant 20–30 years)
3. Key financial assumptions by scenario:

• Upfront cost / down payment
• Recurring monthly cost
• Expected appreciation/return rate
• Tax treatment
• Final value (if applicable: home equity, vehicle value, account balance)

1. User's marginal tax rate (for tax-aware comparisons)
2. User discount rate (default: 7% — long-term real return of the S&P 500)

If the user doesn't know the assumptions, use reasonable defaults and label them clearly:

• Home appreciation: 3.5%/year
• Rent inflation: 3%/year
• Real stock market return: 7%/year
• Real bond return: 2%/year
• Inflation: 3%/year
• Mortgage rate: current market rate (ask the user or use 7% as the default for 2026)
• Property tax: 1.1% of the home's value/year
• Maintenance: 1% of home value/year
• Insurance: 0.5% of home value/year

Calculation Framework

For each scenario, calculate year by year:

1. Cash outflow — All money going out (down payment, monthly costs, taxes)
2. Cash down payment / wealth accumulation — Principal amortization, appreciation, investment returns
3. Impact on net worth — Final value minus the accumulated cash spent
4. Opportunity cost — How much would the cash outflows have earned if invested at 7%?

Total Cost (10 years)

total_cost = sum(annual_cash_outflow) - end_state_asset_value

Opportunity Cost

opportunity_cost = FV(monthly_diff, 7%, 10yr) where monthly_diff = scenario_A_cost - scenario_B_cost

Risk Profile

Rate each scenario from 1 to 10 on:

• Liquidity risk — Can you withdraw your money?
• Concentration Risk — Is other net worth tied up here?
• Income/employment risk — Requires stable employment?
• Market risk — Sensitive to interest rates, the real estate market, the stock market?
• Reversibility — Can you easily reverse this decision?

Output Format

Save to FINANCE-COMPARE.md in the current working directory.