QUOTE(billy08 @ Dec 6 2017, 11:04 AM)
what is the benefit of doing so? In fact, with the higher loan amount, the purchaser will end up paying more interest in the long run.
the variance of $150K, who is going to pocket the money? purchaser?agent?seller?
This is my first time hearing such a case and does it even work? Does the seller even know he is selling at a lower price or not? Or does the purchaser even know the actual sell price is $150K lower?

there is no benefit in the long run, only in the short run whereby the purchaser/borrower gets to take out more money to use. Sort of like a personal loan borrowing but with the benefits of a housing loan. Not everyone is entitled to get a personal loan for such a big amount of money.
If the purchaser/borrower is willing to do that, clearly he is not concerned about the interest charged. What the purchaser/borrower wanted is immediate money.
Any additional monies paid by the Bank will be misappropriated by the purchaser/borrower. Although technically speaking the purchaser/borrower will still pay the money back to the Bank but it is the circumstances which induces the Bank to lend more money then the Bank would have if the actual facts is furnished to the Bank. This is fraud.
It is actually not uncommon for parties to conclude a deal like this. Desperate vendors and greedy purchasers/borrowers, that's all it takes and yes, 100% of the time, the parties know what they are signing up for.