What about the inboard phono pre? If your budget allows, you might consider keeping the Rag you have. The dac included is probably better than you think and better than nothing. It gives you an upgrade path by giving you a baseline. Also, no additional interconnects needed right now. Additionally, resale will be decent with those options installed and moreover, who is to say Schiit won't release nice upgrades?
In the future, you can always add an external dac when the budget allows but you need to get away from the airport express. Definitely consider rendering your music differently than you are currently. Google Allo or Uptone versions. The least expensive options available will kill the airport express sound wise.
In the future, you can always add an external dac when the budget allows but you need to get away from the airport express. Definitely consider rendering your music differently than you are currently. Google Allo or Uptone versions. The least expensive options available will kill the airport express sound wise.