If you get a full CD player or SACD player, from most manufacturers cost is same or higher for the CD player if the DAC is of equal quality. If the unit is just a transport and is only a tray with digital circuits and one transformer, it should be dramatically less expensive.
The cost in great DACs has little to do with the DAC. It is the output stage. That is what really dictates the quality of a DAC. Great units typically have a dual mono power supply for analog and digital circuits typically are handles separately by a different transformer. Also, if a unit is fully balanced it effectively doubles the circuitry as well and this adds a lot of cost to lower the noise floor. .
Analog is where the major deviations occur between cheap dacs and great ones. An ESS, Burr Brown, Wolfson, AKM, Analog Devices, Cirrus Logic chip will all do a competent job of the conversion. It is then the amplification of that signal in the analog output stage that dictates how the dac sounds.
Take Playback Designs. That enormous chassis was so full of stuff for the analog output stage, Andreas had to remove a transformer to make room of the CD tray and servo board for the MPS-8 SACD player and the net impact is that the MPS-8 is a small step down in performance from the MPD-8