@Richman
Nothing stops one from selling the house before you complete paying,but there will be costs,e.g. early payment charges by the lender (which I personally think is theft),and the cost of paperwork (lawyer fees and registration fees etc) which is sometimes even 200K and which you lose when you sell off your house and have to pay for an upgrade.
And the most important thing people ignore is the inflation. E.g you buy a house for 2M and value appreciates to 4M in 2 years,the question is whether the 2M is a real gain or just paper coz if you sold the house,you would still need to buy a similar one at market value so be careful before selling,make sure you know exactly what you are going to do with the proceeds,upgrading is a damn good idea if you have additional funds or if you can now qualify for a higher mortgage.
I guess if you can't win with facts,you can always pen bile-laced,xenophobic rants to distract everyone.
"The purpose of bureaucracy is to compensate for incompetence and lack of discipline." James Collins