Is there a reasonably priced ($30 ish) adapter that can accept component video output and optical digital audio as input at one end and put it out the other end via HDMI ?

Is there a reasonably priced ($30 ish) adapter that can accept component video output and optical digital audio as input at one end and put it out the other end via HDMI ?

Not likely.

You need some sort of video processor to convert the analog signal of component to the digital of HDMI

I agree- this would not be a cheap device as it would require quite a few electronics such as video decoder (including analog to digital converter), HDMI transmitter, and a video processor. There are several brands of video processing boxes that will perform this function, but none close to the low price point that I am aware of.

http://www.hdtvsupply.com/cotohd.html

how can you do this if you have a component hd switcher and coax thru out the house

How about something that combined an already digital set of signals from a DVI output and a coax SPDIF? Seems like there ought to be a way to have a passive 'splitter' that handled this. I realize why one needs a box to handle converting the analog VGA and audio signals, and at $179 that's not a break-the-bank price.