Hey Charles,
Let's look at it this way. A really good DAC like either of the two listed below are about the same price.
http://www.nekoaudio.com/http://www.dbaudiolabs.com/One only has optical and coaxial S/PDIF inputs. The other has a USB I2S direct input only.
Either way you go, the computer audio solution has a big leg up on any CD player or transport from a quality perspective and for many reasons.
So regardless of what you decide to do there, you are still buying an external or separate DAC.
The lowest cost solution that I know of, and according to the in the loop guys that I know that have A/B compared various computer based systems (that's right, they do not all sound alike), the Mac Mini was a favorite.
I bought mine used on E-bay with a wireless keyboard and mouse for $425 (200 gig hard drive too!). I can't even get a good mid-fi level transport for that.