“Cheapest” means the lowest interest charged.
Banker are willing to loan us money for buying houses because that is the most secured collateral. Why bother to settle the loan fast? The interest rate is only BLR + margin = 7~8% at this moment.
I bought adequate life insurance to cover my liability ( including mortgage). Thus, I never bother to settle the house loan. When I got extra money, or saving, I always invest it and make sure that they generate more than 8% return per annum.
That means NOW we got the house, plus extra investment. When I die, my wife will also get the house, my investment, and the extra life insurance proceed. If I die young and fail to achieve my financial goal, at least my wife can achieve her financial freedom instantly!