Video effects over the live webcam stream for a party
I think you are going to need something out of your price range to complete such a task. Video, is far more complex to process in real time, than say a photo, that only analyzes a single frame and looks for simple objects like eyes, nose, mouthlines, as anchors. 

The NewTek Tricaster ($20,000) line would be an option for this, but you'd need a company to come in to do it, and with a workflow pre-established to make this work. 

In short. No, there is no easy way.