Cost These units can range from US$140 to well over US$1000. KVM units come with all sorts of different features: PS/2 support, serial support, OSD (On Screen Display), and more. The unit we are looking at is the Cybex SwitchView 4-Port. This unit is a tad more expensive than some of the other 4-port offerings (e.g. Belkin OmniView). But for the difference in price, which is approx. US$40, the SwitchView has some things going for it that definitely make up for that cost difference. The SwitchView retails at approximately US$200, while a similar Belkin model will run you approximately US$160.
The "Other" guys In many of the computer stores that carry cabling, you have probably seen those cheap switch boxes that are under $50. Stay away from these if you want to actually see one image instead of 10 :). There is a big difference between the unit we are discussing and those $24.99 switchboxes. The Cybex unit and other units like it utilize different technology that produces a cleaner image, and a more reliable unit.