Rent vs buy is tenure plus transaction costs
Ownership builds equity through principal paydown and appreciation, but maintenance, insurance, taxes, and closing costs erode the headline payment advantage.
Short tenure favors renting — transaction costs amortize over years, not months. Long tenure can favor buying if appreciation and rent inflation align with your market.
This model is deliberately simplified: no tax deductions, opportunity cost of down payment, or local rent caps. Use it to frame the conversation, not to pick a winner.