Apart from its use among the bean-counters who talk about maximising company profits, I can't understand why price point has spread so widely in popular American parlance. As far as I can tell, the term is exactly synonymous with price; do people use it the way they do the word 'monies' — to sound clever on the cheap — or is there actually a difference between the two terms?
It basically signifies that one is discussing price specifically in terms of how it relates to the demand curve.
If I had to guess, I'd say its gratuitous use probably started with conversations between corporate executives and accountants where the term was being used precisely, moving from there to other executives who were at the meeting, didn't understand the term but thought it sounded good and so tried to imitate the people who knew what they were talking about, gradually spreading out into the culture from there. So, yeah, fundamentally people imitating each other to try to sound clever.
Price point means a point on a scale of possible prices at which something might be marketed; its meaning is different from the meaning of price, which is (principally, but not only) the amount of money expected, required, or given in payment for something.
People can use a phrase used in a specific context and give it a different, or a wider usage. The reasons people would "adopt" a phrase giving it a different meaning, or would use a phrase in contexts different from the original one can be many, and include imitation.
The phrase price point doesn't seem so widely spread. Looking at the Corpus of Contemporary American, I get the following data (the chart reports the frequency per million).
The chart shows how many times the phrase price point is used. As comparision, this chart reports the frequency of phrases where the word price is not followed by point (which includes also the case where the word price is followed by a punctuation mark).
The common (i.e. outside of the narrow economic contexts where it has a specific and well-known meaning) usage of the phrase is a form of mental-gymnastics or double-think that allows the speaker to delude themselves that they're not talking about anything as vulgar and direct as an actual price.