How to deal with the fact that you're not for everyone

It's incredibly common for someone to start a new business and immediately take the attitude that, because they're new - or small - they need to charge less to get market share.
After all, that's how a lot of big brands started out.
In this article I read recently, there is a suggestion that being forced to share our toys and belongings as a child isn't as noble a lesson as we have thought it was.
In fact, it can really bad for us.
Sharing becomes an obligation that actually makes us resentful.
The trouble is, that when a behaviour is reinforced, it becomes a habit. And habits are hard to shake - especially those that are taught us when we're young.
If you're constantly forced to share your possessions - and young kids learn the value of possession at a very early developmental stage - that sharing mentality slips into every area of our life.
You're sitting down to eat your delicious chicken salad lunch at school and your friend, who has a peanut butter sandwich asks you for your salad - so you share. You don't want to, but sharing is now tied to your morality, so you share, because it's the "right thing to do."
The trouble is that there is a whole segment of people who know that this is an easy way to game their way to getting what they want at your expense.
I refer to them as "price pigs."
They are the people who scour Facebook Marketplace for a $20 desk and ask you to give it to them for $5 and also deliver it to their home. And they will often add some sob-story, such as "my daughter with a terminal illness wants a desk for her birthday and I can't afford it because I'm a single mother out of work.
Just like you've learned that sharing is a good thing, they've learned that they can get what they want from suckers like you.