Why don't you just have your MK1 upgraded to the Limited Edition Signature Series PLUS. It's a large improvement to the unit you have currently. It's going to be hard to beat by any current DAC costing up to $15000. We did tons of listing sessions with many high end DAC's including the Terminator Plus 12th, Holo May lvl3, Bartók APEX and even the newer Directstream MK2 and the Limited Edition Signature Series PLUS always came out on top. This is with level matched and blind listings sessions with many audiophiles on a very revealing system.
Also APS has special pricing for repeat customers. You just have to ask them.