People like your mother-in-law usually have a personality, which is to find an imaginary stimulus. This imaginary thing is the adhesive between her and others. I think you see her "delusional element", but it is not obvious if it is only included in "a few dollars cheaper to buy food" or general values. As you said, you like to take advantage of small things. But such people, in fact, generally need others. What they don't understand is how much they need others. They need a sense of sharing their values with others. This implies that they are "important people" to others.

This type of people, because there is no other way to achieve this, involves the personality formed in their lives, such as thinking that they are incompetent or lack the ability to get support from others, and they are faced with this need. So at some point, they will automatically seek to join a group with the same belief. Generally speaking, family and neighborhood are such satisfying spaces, and all the things involved are those influences that exist in daily life.

Amway, they just introduced a kind of values, although relying on their series of products, but in fact it is an intensified stimulus. Compared with the general publicity in life, Amway's publicity is an unnatural intensity, which artificially increases the stimulation, which is very common in the marketing of quick success and instant benefit. When this kind of stimulation is strengthened, or this ingredient is deliberately mixed in advertisements, customers will be involuntarily mobilized. What I want to say is that your mother-in-law is not without discrimination. In other cases, she will think it is a kind of deception. Only when she needs this unique ingredient, that is, enhanced stimulation, will she consciously believe it. This is also in line with her original intention of learning to scrape, that is, to find a "lack of ingredients in life." In your family, or in your mother-in-law's field, she changed her role, causing a chaotic but lively influence among you, and everyone was mobilized to varying degrees, resulting in unconscious emotions. Yes, your mother-in-law actually did what she wanted to do from the beginning, that is, enliven the life of a stagnant pool.

We can't live without such an event, otherwise people will feel as if they are dead. If you consider your mother-in-law's personality, you will know that she has almost no choice but to strive for an exciting life, which is precisely the driving force for people to cause chaos in their lives. If you mean the failure and disorder caused by blind faith, independent choice, stagnation and deliberate resistance in all families or relationships, it is often because people think that life is too boring and is killing their vitality. So they want to add some vitality to their lives, disturb others and create chaos. This is just a necessary step, not to say that it is irrational, but to say that it is rational, human rationality.