Housing decisions combine financial assumptions and personal priorities. This model isolates equal cash resources, dated housing costs and realizable wealth. A favorable result is conditional on the inputs, not a promise about markets or a recommendation for every household.
Follow both cash ledgers
The renter receives the buyer’s cash-to-close as initial liquid capital, unless separately entered renter fees use some cash. Each month both receive the same budget. Positive remainders are invested; a shortfall uses held cash then investments. Negative balances are disclosed with an entered financing rate.
Separate ownership from sale proceeds
Only scheduled principal and interest are fixed for the entered fixed-rate loan. Taxes, insurance, upkeep, HOA and rent follow the stated assumptions. At the actual sale, the loan and expenses are deducted once. There is no continuing hypothetical home or mortgage in the post-sale path.
Stress assumptions, not probabilities
The appreciation-return grid holds rent growth fixed and previews each pair without applying it. Driver comparisons change one input at a time. A long stay does not guarantee a buying advantage, and no crossing says nothing beyond the finite horizon. Verify taxes and quotes independently.