Video conferencing equipment (such as the cameras, microphones, and displays) has an upfront, one-time cost. However, it can be leased as part of an all-in-one package, too – though this will most likely work out to be more expensive over time.
You may also be liable for other fees, such as a charge to upgrade the hardware, or a recurring fee for maintenance. How much you’ll pay for the equipment itself also depends on the condition you buy it in (new or refurbished), and who you buy it from. Buying directly from the providers themselves is the best way to go, though they’re typically quite coy when it comes to exact pricing information.