The math at the top seems suspect. In all three cases Alice should have "spent" the same amount of money after 18 years. In the cases of renting you pay more each year and get no equity back, so you should be less able to save and you get none of your money back at the end.
I guess the only difference is whether that 20% downpayment on the loan better spent sitting in a house or in bonds/ETFs.
I guess the only difference is whether that 20% downpayment on the loan better spent sitting in a house or in bonds/ETFs.