Where does "MidFi" differ from "HiFi" or "LOFI"?

Given the vast range of product and costs thereof in this industry, I'm curious where the "break points" are between levels of fidelity?   Equipment can range from $100's to $100,000s+, so where is "MIDFI" vs. "HIFI"?

The ear hears from a range of 20-20,000HZ, but mid-range is certainly not at the 10,000HZ level. 

just curious what you all think.