If I wanteded Pinchys pink convertible fiat 500 but nobody else wanted it. I wouldn't need to pay as much as I might if lots of people wanted that car.
Or it was winter.
Or it was a different colour.
The market is Cars. The rate is for the individual product. (With lots of vairiables that make it unique, and therefore only worth what people desiring those attributes want, need and are willing to pay - its rate within the market).
There is no market rate for 'cars'. It's too wide reaching.
There is a market rate for a soiled pink convertible fiat 500 hundred.
I've only put this down as I was getting lost myself

so don't worry I feel like I've waisted my life as much as you will have reading this.