If a buyer is willing to pay a high amount to get an account with +ve trust, that buyer is up to something, buyer is not buying the account primarily, buyer is buying the trust that comes with it. If the buyer is up to something good, buyer doesn't need to buy a +ve trust account.
That's assuming that everyone that buys an account is positive trust is up to 'no good'. Some people buy it to help get their business off faster, or to sell goods. Not saying everyone that buys an account with positive trust isn't up to the sketch, but that's really an invalid generalization.
If only reason is to get their business off faster they can buy an account with neutral trust.
Most of them are just trying to avoid the 360 seconds waiting time.