title_body: What differentiates a $100 coffee machine from a $1000 coffee machine?
upvoted_answer: More expensive coffee machines typically have better "plumbing", including some and even all of the following:
  
  
  2 boilers / HX to allow for frothing and brewing at the same time
  Preinfusion
  Copper boilers vs. cheaper aluminium versions (guarantees better temperature stability)
  Larger boilers, allowing for more shots to be drawn/ milk to be frothed
  Wider portafilters (which in some peoples' opinion gives better flavour)
  3-way valves to allow back-built pressure to evacuate
  a real steam wand, no gimmicky plastic ones that promise the world and don't deliver
  the ability to be plumbed (connected to your water drain so you don't have to manually clear out the water tray.)
  The option of vibration vs. rotary pumps (which are quieter, although I think they are more likely to break if there is no water)
  Customisability of technical factors (pressure, temperature) which gives more control for our crazy data-obsessed coffee needs :)
  
  
  Now this doesn't mean you can't get good coffee on a cheaper machine. You're just going to have to put more effort in it and get more variable results. Which is more than fair for most people.
  
  As for the price difference, most of these features will raise the price by themselves and a lot of the more expensive machines are hand-made as well.
  
  Last point they are also very pretty and a status symbol, not to the extent of let's say a very expensive watch but it does sort of feel that way sometimes.