In general, how does price relate to quality?

I'd say there is a loose relationship between price and build quality (e.g. quality of parts used, level of construction, tolerance...etc), but this doesn't equate to sound quality, which is most important to us.  So overall, there isn't a clear correlation between price and overall quality as judged by the end user.  Is a 10K phono stage 5x better than a 2K phono stage?  How would one even determine or quantify it is objectively better?

Think it really boils down to if it is worth the money.
IME, a much more pricey piece is usually well worth it.

Money can't buy you happiness but it sure can my a lot of misery!  I have said this so many times here on Agon.  Get to know what parts make a difference in sound.  Price has nothing to do with sound or quality unless the component is designed well.  I have a old Lafayette KT-550 tube power amp that probably sounds better than most amps built today.  No special parts but transformers are excellent.  Go Figure. 

Happy Listening. 

@bigkidz , in the absence of a greater misery money sure can buy you happiness and security. However, you only need so much and there are people who really need help.

Buy the best product you can afford and stop coveting what you can't have or begrudge those who can afford to pay more for what they perceive as better. It's all relative.

All the best,
Nonoise