That'd be nice. Here it works differently. 

The big fish gets the service at cost, because if he bad-mouths you you won't have a business. 

The n00b or foreigner (or woman/man, in some industries) pays literally 10x.

I've done some work in mystery shopping, and its hilarious how different quotes can be depending on gender, age and accent. 

 It wouldn't be nice because if the wealthier person went along with it, they'd eventually lose interest in making sandwiches. 

 They'd lose interest in making sandwiches for poor people, absolutely.

This actually happens, of course. Usually caused by government regulations, but social pressure alone has an effect in the same direction. 

 This is one reason why poor people often have trouble acquiring goods and services. 

 It ought to work the same way at the other end of the scale, too. People ought to be reluctant to do business with those more powerful who can screw them over without consequences.

They don't seem to be IRL though. Especially construction subcontractors. They just bitch to me about it, and then go out and get ripped off again... 

 Yes, odd, isn't it?
People are often irrational economic actors. 

 Very true. Culture plays a role.

I've met a lot of small/medium businesspeople here who unironically brag about how much they're being overcharged, especially if its by a household name. They only keep quiet about how much they are also writing off as bad debts. 

Cringe AND stupid, but it appears to be stable for now...