title_body: Does a plumbed, self grinding coffee machine at 300-500 USD exist?
upvoted_answer: I had a friend requesting exactly this for his gym recently and we were unable to find a machine that fit all three constraints. 
  
  The options were basically choose a commercial level plumbed machine with a separate grinder, or a home level grinder / brewer combo and pour water in yourself.  I think there may be some basic technological problems with sticking a grinder right on top of a brewer, since it would probably be subjected to less than ideal environmental conditions (all that water vapor getting on your burrs / into the bulk beans can't be good)
  
  If it is a low volume situation, the Cuisinart DGB 900BC might work, if high volume I would recommend a plumbed Bunn / Curtis Airpot system.