HomeCasa Compare two financial decisions with scenarios
Compare options such as renting vs buying or changing cars with optimistic, base and pessimistic scenarios. Designed for ChatGPT, Claude and Gemini. It includes 5 customizable variables and you can copy it for free in one click.
Intermediate · Text · Pending editorial review
Prompt
Act as a financial analyst who explains things clearly. This is an educational exercise, not personalized advice.
Decision: {{decision}}
Option A: {{option_a}}
Option B: {{option_b}}
Time horizon: {{horizon}}
Data I know: {{data}}
1. List all relevant costs and income for each option, including the hidden or commonly forgotten ones.
2. Define assumptions for three scenarios (optimistic, base, pessimistic) and show them in a table.
3. Calculate the cumulative result of each option in each scenario, showing the formulas.
4. State which variable the result is most sensitive to.
5. Non-financial factors to consider.
6. Which data I should confirm before deciding.How to use it
Change the assumptions and ask for the calculation again to see how the result varies. Double-check the math in a spreadsheet.
Usage example
Decision: rent or buy a home · Horizon: 10 years.
Sample output
Educational exercise, not personalized advice.
1. Costs and income per option
| Item | A: keep gasoline car | B: financed EV |
|---|---|---|
| Energy | 9,000 mi ÷ mpg × gas price | 9,000 mi × kWh/mi × electricity price |
| Maintenance | Oil, filters, brakes… (rises with age) | Lower, but check tires |
| Unexpected repairs | Likely on an older car | Warranty: [FILL IN] years |
| Financing | — | Interest on the $32,000 loan |
| Often forgotten | Registration, inspections | Home charger install, insurance |
| End value | Resale value after 6 years | Resale value after 6 years |
2. Scenario assumptions
| Variable | Optimistic | Base | Pessimistic |
|---|---|---|---|
| Gas price ($/gal) | [FILL IN] | [FILL IN] | [FILL IN] |
| Home electricity ($/kWh) | [FILL IN] | [FILL IN] | [FILL IN] |
| Loan APR | [FILL IN] | [FILL IN] | [FILL IN] |
| EV resale value (% of $32,000) | [FILL IN] | [FILL IN] | [FILL IN] |
3. Formulas
- Cost A = Σ years 1–6 (energy + maintenance + repairs + insurance) − resale value
- Cost B = total loan payments + Σ (energy + maintenance + insurance) + charger − resale value
- Difference = Cost A − Cost B (positive means B is cheaper)
4. Most sensitive variable
At 9,000 miles a year, the result hinges mostly on the EV's resale value and the loan APR…
Key facts
- Category
- Finance · Scenario comparison
- Output type
- Text
- Level
- Intermediate
- Designed for
- ChatGPT, Claude and Gemini
- Verified in
- Pending editorial verification
- Variables
- Decision, Option A, Option B, Horizon and Known data
- Language
- English
- Price
- Free, no sign-up
- Updated
- Nov 7, 2026
Frequently asked questions
Is this financial advice?
No. It is an educational model that structures the decision; for large commitments, confirm the figures with a qualified advisor.
Why three scenarios?
A single forecast hides uncertainty. Comparing optimistic, base and pessimistic cases shows whether the best option still wins when things go wrong.
What is this prompt for?
Compare options such as renting vs buying or changing cars with optimistic, base and pessimistic scenarios.
Which AI tools does it work with?
It is designed for ChatGPT, Claude and Gemini. We have not verified it in these tools yet, so results may vary between them.
How do I customize the prompt?
Click “Customize” and fill in the variables (Decision, Option A, Option B, Horizon and Known data). The text updates instantly and you can then copy it in one click. Values are stored only in your browser.
Do I need experience to use it?
It is intermediate: it helps to know the topic so you can provide good context and review the result critically.
Is this prompt free?
Yes. Every HomeCasa Prompts prompt is free, with no sign-up or subscription. You can also use them in professional projects.
Can I trust the AI output?
Treat it as a high-quality draft: always check data, figures and important claims before publishing or making decisions.