This is a simple setup using a cheap 83cm umbrella and 40cm softbox with two $80 Yongnuo YN-560 manual speedlites triggered with RF-602 wireless triggers. I'd probably put this basic lighting gear at about $350-400 and it's served me very well.
This is by no means the only lighting setup you could use for a business portrait, but it produces decent results.
Getting some cheap lighting gear like this will really open up a lot of opportunities to sculpt your lighting the way you want.
The great thing about using strobes like this is that you're running pretty close to ISO 100 which will yield very sharp results.
You can of course use natural light and use it effectively but I guess it's up to the needs of the design as to what sort of look you need to capture.