A very relative question...also a good statistical study.
I, given my current situation, which consists of - how much I can spend (irrespective of how much I earn because this is passion and not just another appliance), how loud I can play (includes wife and kid's tolerance, which also considers whether I have a separate room or basement to set up my sound system, which I dont), whether i want this for music or movies or both, is this my first serious Sub (yes) and lastly, but not limited to, how much I want to trouble my neighours (i.e. I live in a Townhome), - would spend about $600. Maybe down the line, I may spend more, but being newcomer to this side of the consumer world, I would start with spending less.
I do not own any Sub currently.
-dAre2dreAm