A home appreciating in value looks great β but you're also paying
mortgage interest, property levy, insurance, and maintenance.
Net Value captures the full
picture:
Net Value = what you'd walk away with β everything you paid in
For Buy, what you'd walk away with is the sale price minus the
remaining mortgage, selling costs and any capital-gains tax, plus
anything the buyer invested along the way and any tax savings from
deducting mortgage interest and levies. For Rent, it is your
investment portfolio after capital-gains tax.
Everything you paid in is the same total for both: the up-front costs,
plus each month the larger of the rent and the cost of owning, because
the cheaper side invests the difference. So both numbers are often
below zero.
This tells you which strategy actually leaves you wealthier. A scenario
can have higher asset growth but lower net value if the costs
are steep enough.