I just started playing with this myself...
I'm too cheap and can't justify the cost of a complete set up to the better half, so I've been piecing elements together for the past 10 months or so...
Amvona (Dynatran) background support kit: Ebay approx. $100.00
WF (?) Flash kit(Lt duty stand, umbrella/light grip, reversable umbrella, strobe and pc cord: Ebay, approx. $40.00
Background muslin: Ebay: approx. $30.00
A couple of used hot shoe flash units that I plan to use as slaves: Ebay, $35.00
I plan to use the one strobe with the umbrella as my main flash and the hot shoe slaves for fill and background fill.
Now, I don't plan on opening a studio. I wanted to do some portraiture of the family and didn't want to put out a lot of money. At about $250.00 with maybe another $50-100 more to go in backgrounds and other things, I think I may have the poor mans photo studio...I just started making some test shots today; so we'll see if I accomplished anything.