[Galanwe]

Your calculation is bogus, you are 1) assuming infinite money 2) assuming infinite time.

1) When you say "add sustained regular $2500/mo contributions", you forget that compared to buying your place, you also have to pay rent, most likely at the same amount you would pay back your mortgage assuming same quality of life. So either you have a free $2,500 to spare (in which case you could also have invested that amount in the buying case, or borrowed more), or you have $0 to invest.

2) You cannot just take the expected value of two different returns distribution and assume you would earn it in both cases. That would assume you have infinite time to wait for the average rate of returns to converge. If your life depends on said returns, you cannot just say "oh nevermind I'll wait another 15 years to withdraw". In your example, stock market returns are immensely more volatile than real estate.