Operator knowledge is very important. I often tell people "It is like a table saw...not a toaster" "Just because you have one doesn't mean you will be able to use it right away"

Also, typically the less you spend on a printer the more time you spend tuning or failing prints. You can make a $600 in parts printer do very well if you know what you are doing...but it is much easier if you spend more on parts. Things like linear rails and proper leadscrews go a very long way...as does a proper hotend.