@agisthos The Weiss is a bit more expensive than $7K. You can find a used 501/502 comfortably in this range. It is a great unit and the preamp stage is very good.
You have the secondary concern about system matching though. The Weiss is superb but a hair forward of neutral. I would never say that that is the right unit for you without knowing more about your system The new MK2/4Ch version is about $2K more. There will be an upgrade available to the new board sometime in the new year.
The best preamp stage in the price class (or very close) IMO would be the Rockna Wavedream Edition SE at $7200 and that unit is dead neutral and the preamp stage is better than most. If you don't need XLR connections, the SE versions of these DACs are jaw droppingly good for the money.
In the similar price class to the Weiss MK2 4Ch, the AGD Adante which is a full preamp with R2R DAC inside and is Roon ready. This has a distinct advantage over many of these units as it is a true preamp that has a DAC module in it.