Multiple monitor and video card question

[patient77]

Sorry if I sound like a computer idiot, but how do you add a third monitor if you currently have two monitors running. I currently have a dual monitor video card with two lcds connected, and want to add a third. Do I need to buy a new video card that has three monitor outlets, which I think run over $200, or can I just add a single monitor video card to one of my empty PCI slots on my motherboard?

It just seems way too easy to add another monitor just by buying a PCI video card, but hopefully that is the case. Any help appreciated.

patient77