Some greedy people will try to find or instil uncertainty in people so that they can swoop in and be ‘the solution’

This aligns with the genetic business advice to find a problem and be the solution

Being the solution is charitable but creating a problem to be a solution is greedy

Our time is limited so if you suspect that somebody is trying to sell you something tell them (subtly or directly) to get to the point and to show you rock-solid proof

Avoid purchasing things on the spot, give yourself a day or two to think about it alone and discuss it with your trusted friends / family if necessary