"If you're making $300k a year, you have more in common with someone making minimum wage than you do with Elon [Musk, the founder of Tesla and other corporations]. There are people that walk among us that have so much wealth, that even generations of mismanagement can't squander it. These folks you speak of are not those folks."
It's not an income thing.
Like most of what Marx wrote about it's defined by your relationship to your means of production.
If you own other people's means of production and live by profiting off the gap between the value they produce and what you pay them you're bourgeois.
If you do not own your means of production and are paid a wage to work you're working class.
If you own your means of production but don't employ anyone else to work it (ie, a freelance contractor or independent shopkeeper) then you're petit-bourgeois.
I think the term you're looking for is "labour aristocracy", which was coined by Engels to describe the upper section of the working class who receive high enough wages it can act as a bribe that causes them to betray their class interests.
Lenin extended the argument to say that these wages and the lifestyle labour aristocracy lives is dependent on the profits of imperialism to be sustained, and knowing this they actually have reactionary class interests opposed to the vast majority of workers.