Newbie would like some help building please

Hi, I have been trying to locate a place to get plans for a home cnc
machine, but have come across a variety of costs for them. I have
also noticed that the parts that are used, almost equal up to the
same amount I could buy one brand new for. When I found this group,
i figured I would pose the question to all of you...

Is there a way to make a home cnc machine CHEAPLY? I mean for under
$100 or even $500. If it goes into the thousands, why would I want
to build one? I know, the same reason you build a bookcase instead
of buying one - because you can do it, and it is normally better.

Well anyway, that is the main question I had, and hopefully if there
is a solution, then we can go from there.

Oh - i have seen plans that use a "rotozip" type tool also?? Is this
really viable? I always thought of using a router in it. Maybe if
there is a cheap way to build one with a rotozip, maybe someoen could
give me some info on how the blades react to different hardwoods, and
how long they would last. I know using a rotozip around the house,
that the blades do not seem to last very long at all.

OK, enough for now..:) I HOPE someone can help with this problem,
and find a solution for doing this CHEAPLY.

Thank You
Mike