Trade off? New vs used

Depends. Which one sounds better?

I admit that psychologically it is easier for me to buy something that has already received it's resale value hit :-(

Millercarbon is right though

It all comes down to how it sounds to You! In your case you could try both and return the new if within stated time frame or re-sell the preowned unit.

Sound comparisons tough to do at a dealer. Not set up to swap out preamps and don’t have ones you want to test.

so I buy one new from dealer and another model used from another place or person and do an AB test with 2 units each costing about $15k in my home.  This whole process is such a mess.  
How many people buy stuff after reading/learning without listening, ie. Blind faith?