Learning CNC

This is a very quick question. At first I thought 'When I get the money I'll
just go straight for a mill that'll run from the PC'. But I've found a load
of older machines that are in perfect working order and just need the
attenion of some oil and a can of spray paint. So I was looking at these and
the MASS of manuals that come with them. How hard is it to use these
machines that run on numbers fed in raw? For instance I found a ?Hurco? that
had nothing other than a keypad for the codes. It was something like $2500
because no one was going to the page to bid for it. Is it much harder to use
these things or are they not capable of doing other things that the ones run
direct from my PC can? I don't mind if it takes a lot longer to learn if the
thing is going to last a good 50 years. It may even be more beneficial if I
could use CNC without going through the pretty consoles of windows I guess.
Am I getting completely lost here or is this making some sort of sense to
someone? : )

John